I am currently a PC user, soon to be a PC/Mac user (getting my PB in about 3 weeks). My school's photo class has iMacs that we use, and I honestly don't mind the single button on the mouse compared to the two button mice I'm used to. The main thing that bothers me about the single button mouse is that it doesn't have a scroll wheel, and that the design of the mouse coupled with how I hold it sometimes makes it difficult to click (I have a death grip on the mouse or something..need to work on that). But, between the two, I prefer a two button mouse because they generally have a scroll wheel.