I got a Steam controller.
One thing I'll say about it is that it's weird. It's a bit too big for my hands, so I have to stretch just a tiny bit to hit the X and Y buttons. Not a huge big deal overall but definitely some ergonomic concern for extended play.
I really like the haptic engine on the control pad surfaces. It's hard to describe until you feel it. The pads vibrate so rapidly that it feels like sandpaper or some kind of textured surface. I can't really put it into words but it's a very satisfying sort of feedback to let you know you're moving around.
I haven't yet found a game that REALLY takes advantage of all the features it has to offer but so far it's a solid controller for games that support it.