My 921 arrived this afternoon.
I haven't been able to play with it too much because the weather is HOT (83 - yes we consider that HOT in Seattle).
First of all, I was VERY impressed with the service from Scott and Claude. They even had UPS send an e-mail to notify me that the package was delivered. I've never had anybody turn on this notification before. Since I live in a marina, somebody in the office accepts packages, not me. Ordinarily I don't know if the package has been delivered unless I keep checking the UPS tracking web page.
So far,
1. Haven't been able to get 1080i output working on the DVI cable with my NEC 50MP2. I get "illegal signal" on the TV. 720p works fine.
2. Haven't been able to get RGB working thru my DVI/RGB splitter cable. The DVI side of the splitter works fine.
3. The speed of the guide is FAST compared to my 501 and 6000.
4. The 921 is much quieter than my 501.
5. My digital locals are great. I live less than two miles from some of the transmitters, and less than five miles from the rest, so that may help. Haven't tried recording yet.
6. I miss the grey bars on the side of 4:3 programming that I don't want to watch stretched.
7. Some of the setup functions require that "done" be pressed before you can flip to another function. The 501 and 6000 just let you flip.
8. The HD picture from the 921 via the DVI cable is much better than my 6000 via component.
9. The SD picture from the 921 via the DVI cable is much better than my 501 via s-video. Yes, I know it should be.
I'll fool around with it and report more. Some of these things may have been reported already. I've not done an exhausting search in the forum. I wanted to give quick first impressions.