Going through these threads, a lot of people really like UD 7. Any reason someone with a D1 would go for UD7 instead of UD8?
I did not like UD7 and I choose UD8 because it was built from FRG22D, which is the latest Froyo build. I find it to be a lot smother than UD7, IMO.
I started a thread on the Flash player issue with UD8, and several people are sticking with UD7 until BD can come up with a fix.
If you don't use the Flash player, UD is great. But if you use it consistently like I do, UD7 works fine.
I can't say anything for UD7 since I haven't tried it. But I put UD8 on my droid this morning and OC'd it with a Chevy kernel and it rules. The stock theme is awesome, and it appears very stable. The only thing that force closes on me is the UD live wallpaper, but I don't really use live wallpapers anyway. UD8 is working so well at the moment, that I won't bother trying UD7.