Photoshop: Mac vs. PC

I've been designing using my rather high-end PC (or at least it was when I got it 2 years ago). But, now it seems as if Photoshop is just sluggish and it tends to hang-up every once and a while for short periods of time.

I am thinking about getting a Mac laptop (or desktop, depending on how much I can get) to use for design work. The only thing that concerns me is if there is really much of a difference between using programs such as Photoshop on a Mac rather than a PC.

Does anyone have any experiences that can compare the differences?