I had the Surface Duo 1 up until yesterday. I had it for about 8 months. It works. It is nice having a second screen (or a wide screen if you open it up and use it that way). Functionally, I have no serious complaints.
But, I think every review should strongly emphasize that the Duo (1 or 2) is enormously fragile. I have had a dozen cell-phones in my life, and as careful as you are with them, sometimes things will happen. They will slip from a pocket, or a dog will knock them off a table, etc. The Surface Duo is like a glass bottle. Your drop it...even once, and it is very likely to break.
The design prevents the use of any real protective case. Yes, you can glue the provided rubber strip around its edge. But, the thing is entirely made of glass. The screen and back surface: glass. So, my first break, I was getting down onto the floor, and the phone fell 1' onto a wooden surface. shattered the back panel. The phone still worked, but it did not close properly, and did not seem to always know whether it was open or closed, or which screen I was using.
The second (and final) drop was yesterday. Getting out of the car, it fell from my pocket, and more of the back panel shattered. Now the screens won't come on, and it is essentially done.
If you are a person who carries your phone in your pocket, or who is even mildly active, seriously re-consider getting this phone. It is fragile.
The Surface Duo 2 is made of the same materials as the Surface Duo 1, so I see no reason why it would be any less fragile to even the slightest impact.
Mark