Xcode 4 does a nice job of pointing out objects you may have forgotten to wire-up in IB. Prior to that, I struggled with IB. I realize now there is a cadence to it. Declare, synthesize, wire-up, implement delegate methods. Forget a step and your on StackOverflow face-palming.

I tried to get into iOS about 3.5 years ago. I failed miserably. IB was a big part of that...

Trying to get two objects to line-up horizontally with the designer in Eclipse... Well, it makes me want to punch something.