Having a little disagreement on the team about screen transitions. Should we steer clear of the built-in iPhone transitions like flipping and sliding? I think this looks a little amateur, but maybe I'm being too picky.
I think it depends on the app. The thing is that these transitions sort of indicates different things and you have to ask yourself what you actually want to communicate.
Flipping in my mind shows the "back" of the window and makes perfect sense for settings etc. for the windows it flipped from. Likewise, sliding clearly demonstrates a change in place. Just using them for eye-candy seems tacky at best. For normal switches between screens with equal importance I would generally stay clear of any transition.
Absolutely use transitions. If they are used too much, maybe they are tacky, but transitions are very useful for moving between views. I would say that if the transition draws attention to itself it is a bad thing, but if it is used in a subtle, natural way, they can be very effective.