> The opposite. XCode was "atrociously buggy" in the 3/4/5 era and before, and has gotten quite better in the 6/7 series (despite having to support a whole new language).
Xcode 3/4 were a lot harder to work with (IB and Instruments separate, had to use Clang on command line etc), but I don't recall them being particularly buggy. Xcode 7 with Swift is the buggiest version I have used. It crashes on me 10+ times a day with all of the instant compiler checks it does. The progression from 3 to 7 is amazing, but I feel it has come at the cost of stability.
Xcode 3's code completion made everything run so slowly that I had to turn it off, and for a while I just copied and pasted method names out of the Cocoa header files.
Xcode 3/4 were a lot harder to work with (IB and Instruments separate, had to use Clang on command line etc), but I don't recall them being particularly buggy. Xcode 7 with Swift is the buggiest version I have used. It crashes on me 10+ times a day with all of the instant compiler checks it does. The progression from 3 to 7 is amazing, but I feel it has come at the cost of stability.