In the past, have the Mac and PC versions of PE/P had exactly the same functionality?
Once upon a time that was the case. and after adobe spent several development cycles trying to make mac and pc versions of all their flagship items exactly the same cross platform, they departed from that attempt at cohesion. Why? um, dunno. Adobe makes a lot of choices i just don't have the information to fathom, and i think they ignore some very key user aspects to the problem when they make some of the decisions that they do. For example, is there any dang-blasted reason you can think of why it is necessary to change implementation of actions in EVERY version of the program? if anything has put a damper on my development time, I would say that was the biggest hamperer. Granted i don't expect them to think about ME, and really i am probably one of few who benefits from the constant change, but you'd think they'd get a plan and stick it out a bit. For example, in Photoshop i have been reporting the same actions bugs since version 7...they seem content to keep those.
They do know things that we don't, i can be assured of that. But I would think consistency was a benefit.