I'm sure you can go back to a previous backup as usual. Haven't tried this rom yet. It replaces the baseband though. Not sure if you can flash without baseband. Also, there is no sbf for 3.0, so if it goes bad, i think it can go very bad-correct me if I'm wrong someone.
It is a blur rom and being so, it is slower than some custom roms that are out. That is why i haven't tried it. Pretty spoiled with the other that are out now.
I haven't tried restoring my backup over this, but it did a kernel update. I also haven't tried the latest .sbf. Sadly P3Droid posted on twitter that the days of full phone .sbf's is probably coming to and end. I'd suspect motorola is to thank for that. That being said id imagine you can sbf with the existing leak since it's the same system just a newer blur and kernel. I dunno, I haven't really gotten into this Droid 2 much since the devs favor the X. Kinda waiting it out on this phone staying mostly stock until I see what the next gen has to offer. I'll probably follow the devs that time.