So far, XCode 4.3.2 has been irritating.  It crashes far too often.  But here is some of what I’ve learned:

Get a funny response from copy and paste in Xcode? Strange response from Xcode from undo?  Did the change not appear in Xcode?  Did lines disappear from Xcode?

These kinds of things usually indicate that a crash will be happening soon.

Sometimes I can recover by changing to another file, then changing back. This does seem to help keep Xcode running.

My editing habits probably contributed a little. I tend to scroll around, then use undo-redo in quick succession as a way to go back to where I was in the file.  Usually this was fine in previous versions, but Xcode 4.3.2 seems to crash a lot right after I do this.