I do One Pitch almost all the time, like others have said I occasionally do PbP for important/tense situations, more to drag out the tension than to get any kind of advantage. I usually PbP the 9th in close games, for instance.
To be honest, a lot of the time in the first few innings I just sim by half-inning.

I stop doing that when we get to the pitching changes (so around the 6th unless things have gone horribly wrong) because I like to choose the pinch hitters and such.
I also turn warmups off, because I constantly forget, and it's not very realistic to throw a guy on the mound cold because you 'forgot' to tell him to warm up.