I was going to say that the big downside was that it was Windows OS instead of Palm OS, then I saw that little "P" hiding there at the end. Sweet!
If you upgrade, let me know. I might be interested in your 650, you're on Sprint, right? Verizon doesn't work very well at Venus's new barn so I may want to change cell providers, but my Treo 650 will only work on Verizon and I don't have the bucks to buy a new one.