Very good cart for the price.
I sit in an easy chair and do work as a freelance web developer on my laptop with this cart.
I am on a medium thickness carpet and although I thought it might be unstable when I first put it together after getting it in place at my chair it is more than stable enough.
I wish there was one with a telescoping table because the reach of this, and the others I've seen, doesn't really clear my arm rest.  Angling it seems to work well though and serves my purpose just fine.
I imagine a telescoping cart would be rather unstable and probably tilt.
Side table nice for a drink etc.  Could work for a mouse also but it is not adjustable by itself.
Tray is as deep as it is wide and this seems off because most laptops these days are landscape in shape.  Any bigger than my about a 17" screen and you are gonna run out of space.