I really want one, but mainly because it's "new and shiny." I just got my 500 model working perfectly, so a bit pricey to upgrade because it looks a little different. I'm also tempted because the new one seems to work better with a Mac.
But I've put this much time into figuring out my 500 I guess I'll stick with it. Maybe. Probably. Um, wait I DO have a Christmas bonus on the way from my job. Hmmm...