Overall, I liked this enough to purchase more rolls for additional rooms in my house. Due to Covid's SIP, I've been in my home office most of the day and when you're on Zoom calls, door is closed, making the room kind of hot as my house is on the sunny side of the house.

First of all, does it work? Yes, absolutely. Removing the miniblinds from the window on a hot day, standing in the window to clean it off, it was pretty hot. As soon as I got the tint film up in place, not even done yet, you could feel a difference. How much? What I did today was using a laser thermometer and measured the tinted window vs an untinted window in the room next to my office, and the miniblind surface itself. There's two things going on:
1) the mini-blind's surface was about 10* F cooler in the tinted room. I consider this the best indicator of how the tint is effective at keeping the heat out since that's on the direct surface itself of the miniblind, the closest thing near the window, first thing the light that passes through hits.
2) ironically (or not), the window surface itself of the tinted window is 15* F HOTTER than the untinted window. I think what's going on here is tinted window is darker, so perhaps that's holding more of the heat/light on the film, not letting the light/heat pass into my room. In the untinted room, the window is just letting more light and heat through, so the surface of the glass is cooler. So while the tinted window is keeping the rest of my room cooler, just be aware that the surface of the tint is hotter, which probably will create a slight ambient warming. However, i think the benefits of the tint blocking and absorbing the heat is better than it radiating through into the rest of the room.

One problem I did have was that part of my roll had some scratches/folds in it. I immediately noticed this when i unrolled it, but I put the film up anyways rather than return it. It looks like crap on those parts, like some pretty deep scratches. Unfortunate, so taking a star off.

Note that there is no kit that comes with it. I had purchased the NASA TECH garage door insulation and I used the squeegee from that kit for this, and it works fine. Make sure you use a soapy water spray on the surface as well so the squeegee will glide over the tint film easier or you'll end up with light scratches (I got plenty of scratches as proof). The instructions say to use the backer film as a surface to protect the tint film when you're using a squeegee but I don't think it would work so well when you're doing the final steps to help cut along the edges -- it would get difficult.

One thing I noticed was after putting up the tint, there was still enough moisture trapped between the tint film and the window surface, leaving a greasy looking haze. Don't worry, 2 days later after being in the sun, it heated it away. The next day, much of that moisture collected together and created larger bubbles, so I just wet the tint and squeegeed those out, so it's good to go now.

This was nice thick tint there were a few creases and I prefer the black tint and wish there was a wider role

Bought this as it is advertised to keep 85% of UB rays out.

As someone who lives in the desert but also enjoys keeping my blinds open this was a no brainer purchase. Shopped around for a while and landed on this one.

I purchased the silver/silver option. In the larger sizes rolls.

I ended up installing on my back glass sliding doors and my side windows.

Glass doors - 90 x 27 - x2
Side windows - 56 x 24 - x2

Installation is fairly easy. With the size of my windows I did have an extra hand. As it could be difficult to peel off the backing while trying to apply. After spraying the windows with soapy water and placing it where I wanted it I set it on. I used a blade I bought in a film installation kit on Amazon for like 8$ and it worked like a charm. I would definitely recommend a new blade and a squeegee. The other tool that was a huge help was a ruler. Especially when you are cutting corners and edges.

After my cuts and trying my best to perfect it. I. Worked the bubbles out of the film. Occasionally removing the film, respecting the window and re-applying. The bubbles came out fairly easy. Although no matter how much I worked it out there were tiny bubbles that still remain. Please BECAREFUL. This film does scratch easily. I used a squeegee with felt and still managed to scratch parts of it.

I have read from a few others that they went away after a while. So if it doesn't I'll come back and update my review.

The color of the film is silver/silver. I would say it's pretty close to a one way mirror but you can still see inside if you are close enough. I would say from 5-10 feet away you probably get a 5-10% visibility rate in the middle of the day. If your at the window you can probably see 15-20% of the inside (depending on lighting and time of day). The color of the film has a bit of a tint or very very slight fog from the outside. I don't know if that's temporary and will go away.

Pros -
Easy to Apply
Keeps the heat and sun out. But does not block light entirely
Value for the price
Privacy factor

Cons -
Slight fog
Easily scratches when applying - BECAREFUL when working out bubbles.
Creases easily

For the price and the amount I received I would recommend it.

This is not a paid review.

I will be sure to update my review if quality drops off or if it exceeds my expectations.

(in the photo there's mirror film in the center and rainbow film on the edges)

Efficacy: It works. I have stood outside, face against the glass, in the middle of the day, and cannot see my cat sitting in the window on the other side. Yes it's see through at night, but that's how windows work.

Brightness: I originally covered my large window completely with the mirror film, but as some people already noted it made the light coming in very gray and it seemed like it was always a cloudy day, even in a Texas summer. So I covered half my windows in rainbow film instead, which gives off a much whiter light but is very hard to see through. I'd say it's a good compromise, I like being able to see what's going on outside. (Look up wallpaper joining techniques if you're trying to match pieces of film on one pane of window like I did.)

Application: they don't tell you just how much you're going to need to clean the window. Cleaning it in a standard way will be fine but it won't stick very well. Personally I cleaned the windows with soapy water and steel wool, grade 0000. This grade is safe for windows and will help get much more grime off of the window than you realized was there. I've used it on my cars for years. (But of course you should always check your window to make sure it will be okay.) You can also use a razor blade but that's pretty time consuming and I find the steel wool goes faster.
These windows are single-pane, very old apartment windows so they had a lot of paint splatters and built up grime. They also have sealant sticking out of crevices that I could not clean off. The film would not stick to that and I had to cut around it so that it didn't create air pockets.
The film is hard to peel off of the backing. It wrinkles very easily and that wrinkle is permanent even when you apply it to the window, though from far away they look like smudges. (I did not have this problem with the rainbow film.)
Even though the mirror film says you can reapply it, I have had problems with that. Since I changed up the style I had to pull all the sheets off and cut them to put on the rainbow film, and some of the sheets will not stick back to the windows. One sheet falls off immediately, another couple of sheets slowly peel off over a few days and I have to get them with soap and the squeegee before they come all the way down. The other sheets have stayed up fine though. And the sheets that I did in another room, that did not have to be changed, have had no issues at all.
Temperature wise I have had no issues so far. It stood up to 90+ degree days and it's been getting into the 40s at night now. I'll have to see how it holds up to colder winter temperatures. I do think it has helped with the internal temperature, it definitely seemed like the AC was running less after I got all the windows covered. I doubt it will insulate much in the winter.

*******Edit******* it turns out that I had put on pieces (that were reapplied and wouldn't stick) with the wrong side facing the widow. I fixed that and they haven't had an issue falling down since. However the corners have permanently curled, see photo.

**********Second edit*********
They stayed up all year long, in both freezing and 110 degree weather. They came off fine when I moved and I've trimmed them and put them up in the new place. I rolled them up for the move but they got even more wrinkles so I did end up trimming those out.
Aside from the wrinkling issue they've been great and I appreciate the added privacy.

While not perfect, it's an excellent investment. We have A/C issues and high ceilings and we bought this to cover the worst windows to help bring the temperature down. We bought the black silver tint. The most immediate difference I could tell was the temperature on the carpet where the sunlight was hitting went down drastically. As for the window itself, the dimming is sufficient while still allowing a comfortable amount of light into the room. It won't black out the window but it's similar to having shade trees in front of them, or like when the sun is setting in the evening. It's like having sunglasses as windows. No complaints there. But this is definitely a two person job to install. Measuring and cutting is simple and straightforward but the challenge is sticking it to the window without getting air pockets. It's a catch 22. It sticks to the window easily and I don't think I'll have issues with it falling off. But the strong cling to the window makes it tricky to slide around and adjust or straighten out once in contact. If you need to readjust, I recommend peeling it off and try again. This is where it helps to have help. Take your time lining it up and sticking a little at a time, limiting as many air pockets as you can, and the better it will look and the less bubbles you'll have to push out. We were able to remove most of the air pockets with a cloth, but you're inevitably still going to have a few here or there. It's not a big problem with the blinds down but the imperfections are more noticeable from the outside. First impressions with a few air pockets, soapy bubbles, and darker windows was that it felt like we were looking out the windows of a submarine. From the outside, it provides privacy during the day (kinda looks like smooth tinfoil on the outside, or a mirror), but I'd still keep the blinds closed at night. All in all, I feel like the tint will serve its purposes as a product, but it comes down to the buyer to install it neatly. I think it will pay for itself in time in energy cost. It doesn't take long to put up at all but that depends on how big of an area you're covering. We'll see in time how much it keeps the heat at bay.