I guess that's good. Tried Xcode 3. Seriously, horrid mess. Confusing. Documentation that was wrong. Not just somewhat wrong, but wrong, can't compile, can't even do what the documentation say. Confusing madness. A dozen windows open from multiple programs.
Yeah, I haven't gotten a chance to try my stuff under 4 yet (blol Apple changing how the original window is generated and breaking apps), but an IDE where I can not have 47 windows open at the end of a dev session? finally!
XCode is finally catching up to eclipse... hopefully soon I'll be able to program in it without feeling like I'm only a quarter as productive as I need to be...
Xcode already has a single-window mode, if you don't want to work with multiple windows. You'll also want to learn about the Close All Windows command (Command+Option+W), which closes all windows of the same kind. You can use it to close all source windows, all debugger windows, etc. The same command works in most OS X apps.