Here are some observations on memory. I wasn't able to really evaluate performance because I don't have the iOS 5 SDK yet, so I couldn't put it on my iPad. I did test it on an iOS 4 iPod touch, which couldn't get to the Arcade due to memory, but was able to run in the level editor, which baffles because the level editor uses more.
- There are longer then ideal times when the screen is pure white between scenes. I haven't seen this happen with other games I've run.
- Memory usage is odd. Entering credits jumps it by 4 MB, OK. Returning to the menu doesn't reclaim it. Re-enter, and nothing further is lost.
- Game loads - 29 MB. Enters splash 18 MB, then back to 30 MB. Interesting pattern to have it dump memory only to load it back again.
- Level editor jumps by 9 MB, exiting doesn't seem to reclaim anything. In fact, it does up by 1 MB. If I re-enter, it jumps up another 5 MB, leave it does the same thing.
- Entering arcade mode jumps by 7 MB. Exiting reclaims 4 MB. Rentering jumps by another 7 MB., and you can see where this is going.
- Similar story for Level Share.
- Memory usage once you're in the game is steady and properly clears out after each scene.
- I notice that some atlases stuff iPad and iPhone graphics in one.
We ought to get to the bottom of the memory situation. It could be bugs on my end, or it could be on yours. The general problem isn't really that it's high (it is, but that in itself isn't a problem), but that it's not able to reclaim it all and actually is worse, in a sense because it tries to load over and takes up N times the memory.
So the gist of is that we should figure out the simplified scenarios in which this occurs, and then that's something I can work off of.
As for performance, I'll let you test locally with the various older versions and get back to me about that.