This is intended to help others make decisions. My wife purchased a Keurig K450 coffee maker direct from Keurig in June 2017. I bought this refillable pod shortly thereafter. I wanted to use to to fill my 20 ounce Contigo travel mug each morning. Here are my results.
1. The pod worked perfectly fine with the Keurig menu. When using the pod, I get the full Keurig 2.0 menu.
2. Yes, the pod will allow some very very fine grounds to get into the brewed coffee. These are so finae and so few that they're a very minor nuisance to me...i.e. no big deal at all to me.
3. The pod alone will not allow you to choose/use the carafe options. In order to do this, you must also have a Keurig carafe or trick the unit with a magnet. By using the magnet trick, I found that even the smallest carafe setting of 2-3 cups was just a tiny bit too much liquid for my 20 ounce Contigo mug. So bottom line, even if I readily had access to the all of the carafe options using this pod, they wouldn't work well for my Contigo mug.
4. To fill my 20ounce Contigo mug, I simply choose option 2 and select a 16 ounce brew. When that completes, I open/close the pod chamber and then choose option 4 and make a small 4 ounce brew. This gives me a nice full 20 ounce brew. Yes, it's a nuisance to have to do the brew in two cycles, but it's a minor nuisance.
5. This is just a tip. The Keurig K450 does not have enough room under the brew area to fit in the tall Contigo 20 ounce mug. However, I made a simple spacer out of some scrap 3/4" wood (see it at the bottom of the Keurig in my attached pics. This mere 3/4" spacer makes allow perfect clearance for the Contigo mug and is totally unnoticeable to anyone unless you point it out to them.

if you don't have slides at the bottom of the cup you're not doing it right ! We purchased a few of these and preload them with the coffee grounds of choice. We find a regular grind for our coffee works best. I don't recommend fine grind or espresso grind it tends to clog up the filter screens. And for all of you babies complaining of the sludge at the bottom of your cup get over it. This filter allows the oils from the coffee to be released for a robust cup of coffee. Not that I would ever spend $4 on a cup of coffee from Starbucks but what I have heard is you get the sludge at the bottom of their coffee too!

We have used Eco-Carafe for Keurig 2.0, K200, K300, K400 everyday for over a year now. I purchased 5 of these and love love them. They have saved us so much money not having to buy the prefilled disposable name brand and the coffee we like isn't always easy to find in them. They wash up easy and we will continue to use these. Shipping was fast. Plan on buying a few more . They work great so don't hesitate if you are thinking about them . I Recommend Eco-Carafe for Keurig 2.0, K200, K300, K400 .

Just received my Eco-Carafe Pod that allows you to brew a larger batch of coffee today and used it twice to brew two 12 ounce thermos cups of Cafe Bustello. It worked perfectly with our new 2.0 k200 plus. Gives access to the large pod menu. To me the Keurig reusable pod for brewing one cup made weak coffee unless set to strong for a 6 ounce cup, which isn't enough for my coffee addiction. The Eco-Carafe Pod looks to be the same size as the Keurig cup pod, but uses the entire interior space. The hinge on the Eco looks delicate, which makes it harder to gently tap out the grounds. Like the twist lock of the Keurig better. Not sure why Keurig doesn't sell a reusable carafe or mug size pod, I was disappointed and was considering returning the k200 until now. Don't think the Eco can produce enough strong coffee for a full carafe, but you may prefer a milder brew.

I have no idea how this product got so many positive reviews but I was certainly duped.

1st attempt -
I filled it completely with coffee grounds. Placed it in the Keurig, chose 4-5 cup carafe, and pressed the button. So far everything is fine. The stream of coffee begins to come out and the first 2 seconds are a nice, dark stream. It slowly becomes less and less dark until it is just pure water. The end result looks like a pitcher of bourbon. Not good for a French Roast.

2nd attempt -
I hypothesized that the grounds may have been too packed the first time and filled it less completely with coffee grounds and made sure the grounds were loosely packed. Same exact result.

3rd attempt -
I searched google for an hour and found a suggestion to allow the filter to sit in a water/vinegar solution to clear out any oils that may be clogging the laser cut holes. I left it in the solution overnight. The next morning I fill the filter to the top of the silver (a little more than 1/2) and chose a 14 ounce cup rather than a carafe. I saw that after about 5 ounces the coffee coming out was noticeably lighter so I switched mugs. The first 7 ounces tasted like wewak coffee and the last 7 tasted like tea.

Suggestions: I read several reviews saying that the pressurizing system in this product is poor and that the bottom portion of grounds are not properly turned into coffee. Some suggest removing the cone that dispenses water and move it lower - why don't they do this in the first place? In my trials the "bottom portion" was essentially the entire portion.

Bottom line:
After several honest attempts, I was able to create a poor cup of coffee with great effort. I was unsuccessful in creating a carafe of anything resembling coffee. Cannot recommend.