I'm dubious...
I've used Steam Controllers since they first came out - I'm a huge fan of thumb-pad control for mouse-centric games. Perfection.
But... on the new controller the X,Y,A,B buttons are a long way from the pad (and in the opposite direction! That's going to break my brain)
I guess we just have to trust that the bazillion test players at Valve found the layout works.
(And if not, I horded a bunch of V1 controllers...)