I just loaded up Paint Shop Pro 7 (a graphics app, like a lightweight Photoshop) on XP under Parallels and I'm getting a bit of lag when painting. I have a tablet and I use Photoshop, Painter, and Paint Shop Pro with it regularly. Paint Shop Pro is only available for Windows and I would really miss using it. I notice that when I paint fast, I get some serious lag behind my strokes. Is this due to (1) the weak integrated GPU being shared between OS X and XP or (2) just the fact that Parallels is a virtual machine and will never run that fast? I'm perfectly willing to upgrade to an Apple tower in the future if having a better, dedicated graphics card will mean improved graphics performance, but I need to know if it's a Parallels limitation or a graphics card limitation.