The OS lag is a pain, especially considering this is supposed to be an upgrade to the 8700. But the bigger deal breaker for me might be the keyboard. For quick texts or inputing contacts it's fine. But for long emails it becomes a leap of faith. There is simply not enough of a "snap" in the keys to let you know you've hit them. The spacebar is notoriously soft and quiet. I find myself looking down at the keyboard much more frequently than I did with the 8700. I can't say I've made more mistakes typing with the 8800, but the experience definitely leaves much to be desired.
If the early reports on the 8300 are correct ... if its keypad is similar to the 8700 ... I may seriously be considering "upgrading" yet again.