Any recommendations regarding upgrading the Apple SDK?

I still have Xcode 4.1 installed, as I hesitated to install the latest version of Xcode while Unity is some weeks 'older'. Same for my iOS devices which are on iOS version 4.3.

Should I upgrade XCode? What do you think? Any experienced developers out there who can share wisdom on this matter?

I hope Unity 3.5 will arrive soon, be compatible with SDK 4.2 and solve some of the hiccups that we're having to deal with at present...