Installation of the door was fine, though it does leave gaps on both sides...inside the track and against the sliding door side. Some weather stripping fixes that for the most part.
They include a long piece of weather stripping/glass sweep stuff, that closes the gap so cold air and bugs don't get in. However, the adhesive they provide doesn't stick very well. Installed for less than 12hrs so far, and it's already fallen off several times. Soooo, plan for something else.

The door itself feels pretty well built.

It's a great product and it is pit bull proof lol. It would be perfect it didn't leave a small gap

Easy to install, and durable. Good for large dogs and lightweight flap

My cat likes to sit on the outdoor balcony to watch the birds and the birds watch her. She would constantly meow to be let out and in again so someone recommended I get a pet door for the sliding glass door. I did not know that such an item existed. I did some research and this product did all that I needed at the best price. I was apprehensive whether it would fit. I measured the door frame several times and then placed the order. It fit just fine. Since I am a tenant I did not permanently install this insert for the sliding glass door frame. I also do not live on the first floor so burglars were not my primary concern. The insert has a spring mechanism at one end so you can easily insert or remove at will. The only problem I had is not even related to the product. The installer of the glass door did not level the frame and the entire mechanism leaves a gap. There are multiple videos on how to easily correct this but my sliding glass door is a lemon. There is no adjustment screw so I put in a maintenance request with property management. The maintenance person was just as confused as I was because there appears to be no adjustment screw. Also, my sliding glass door is not full width. So with the insert the space for entering and exiting is reduced significantly. In order to bring items in and out of the balcony I have to remove the pet door insert to allow enough room to access the balcony. Again, these are NOT issues with the product. The product is exactly what I needed and performs as promised. The glass panel is especially thick and durable. The issue I have is with the existing door frame and inferior workmanship that detracts from this great product. It was worth the money and even though my set up is flawed it works fine. Only took my cat about 24 hours to figure out the door. The dog took much longer and he is still timid. Magnetic closure on the pet door flap is secure and works well. I would strongly recommend.

I wanted to wait a full year to give this door a proper review. I live in the Midwest so our weather is pretty unpredictable. I've had days as hot as 110 and days as cold as -20, crazy winds and anything else you can imagine. First I would like to attest to their amazing customer service team. The first door I received I couldn't for the life of me get installed. I called to their customer service team and after only a short time on the phone with one of the most pleasant representatives, I had a new door shipped and on its way. We figured that the old door was slightly bowed causing it not to fit (see image). Now for the review of my PetSafe Dog door:

Pros:
-Ease of installation once proper door was received (we screwed the door into the frame for a permanent hold)
-Convenience (I work 13 hour shifts and now my dog can come and go as she pleases)
-Freedom (My dog can run and play outside and still have the comfort of my home within reach)
-Good insulation ( its only a single-paned glass door, but I haven't noticed any change in any of my energy bills)
-Resistance (The glass has held up just fine in extremely cold conditions)
-Gaps were no issue (The gaps we did have were easily covered with weather stripping, I didn't notice any extra bugs in the home)
-Great price. (You can spend over 700 dollars to get a fancy collar activated door or a door with double or triple-paned glass but this door was perfect for me at a price that was very reasonable)

Cons:
-Door flap is easily pushed in by the wind. You could remedy this with additional magnets, but I never really noticed a problem with it opening and closing with the wind.
-A person can fit through the large size dog door. My dad made sure to prove it by crawling through the door and he's a grown average size male. We have cameras set up all around the house, so this fact didn't really bother me.
-My cat now brings me all kinds of gifts from the outside (dead and alive small animals)

I would highly recommend this door to anyone that works long shifts or has problems being able to let their pets out frequently. The cons were no trouble for me and the customer service was top notch. This is by far one of the best purchases I have made on amazon.