To me its harder to play diffrent classes all on ther same pc. I have ran up to 3 on mine 3 of the same range class or 2 and a healer is fairly easy. When you want to 5man a instance or do hard stuff like that to me you need more PCs. This is what I think anyways not sure how much easier it is since I only use one pc. Also I was doing like you at first just clicking the window to cast and stuff and you will like something like http://www.dual-boxing.com/forums2/viewtopic.php?t=17 alot! Im still trying to figure it all out but just for the simple 1-0 key strokes going to all windows is nice.