It's working great on my iPhone 5, but YMMV. I installed it on a friend's 4S who is looking to develop w me, and he is saying today that it won't play any music or podcasts, which is a bug I haven't heard of on these forums. I'm going to take a look at it, as he's not as familiar with these betas. But it sounds like the 4S may have some major issues that aren't showing up on the 5.