Xcode 4 was a definite backward step in UX terms, in my view, from which the product has yet to recover. Xcode 4 has the dubious distinction of being one of only a handful of products that I've used daily for a good period - in Xcode 4's case, 20 months - without ever finding a way that I could be happy using them.

(Sometimes I just throw my hands up and decide that something, whatever it is, is just never going to be my cup of tea, and that's that. I've done that with a few software packages and/or styles of working. But in Xcode's case, I'm pretty sure it's them, not me. Because Xcode 3 was fine...)