I use the Sparrow framework and find it to mimic the Flash's API more closely, and the API as a whole is less complex. The primary downside at this time is that the community is less active/developed, but the author is very helpful when it comes to answering questions.

No, sorry. Cocos2d is the first I've tried using, as I only just started iOS dev.

edit: A quick peruse through some github samples from their framework, and it looks like their API is busier, but seems to be less mature. This is from five minutes of browsing so may not be completely accurate.