The 8830 is woefully underpowered for today's applications. I get a lot of email and the 48MB is gone very quickly. As a result, the whole phone is slooooow. I'm not trying to do anything fancy here, just dismiss a few reminders and check a few web pages and the thing can crawl to a standstill.
Nicer screen, BB OS 4.7, it's a big step in the right direction.