An update: after several long hours of carefully reading several threads, meta-doctor wikis, videos, wondering why my phone "needed" to charge (even though it was full) I've upgraded to 2.1. I may have been a bit over cautious but it seems I've done everything correctly and haven't had any issues with appears, profiles etc.
I think I'm glad I waited a little longer than some. My first 3 downloads after upgrading were Preware, Govnah, Uberkernel.
Overall, (still on Day 1 of real use), I'm pretty happy with it so far. No Flash yet, that's tonight's gig.
I'm finding 2.1 overclocked at SS 1K/500 doesn't seem a whole lot faster than 1.4.5 at same overclock, but I'm ok with that.
Biggest difference that I've noticed that's making it all worth while:
I've lost 8% battery (from full) in 2 hours, which was unheard of, at my level of usage....used to be closer to 20%.
So all other benefits aside, that extra batt life is the bomb.