Thanks for the info Mike and welcome to the forums. I’ve also ran into my fair share of little quirks, but overall I’m a big fan of Cocos2d.
I noticed that you are having some performance problems on iPad1. Here are a couple of suggestions. Use CCSpriteBatchNode for rendering to reduce draw calls. Compile to ARM instead of THUMB. If using a physics engine decrease the steps to 30 per second. Use a code profiler to find bottlenecks.
Visual Studio 2012 Premium has a nice profiler built-in and I’ve noticed that usually Cocos2d only takes a considerable amount of processing when I’m rendering a huge amount of sprites. I’m really not sure how well XCode’s profiler works though.