I have the 661 shorts. They have small overlapping plastic sections that cover the tailbone and part of the sacrum, but not higher. I only wore them a few times on the GG, they are not as comfortable as good bicycle shorts with gel pads. I now wear them riding my Hyper under Joe Rocket pants as I like the extra protection, plastic thigh pads, and with a gel seat on the bike they are comfy. Plus my jacket has a spine pad. I now have a better ('08) seat on the GG though so I should try them again to be fair.
Check this out for another option, maybe what your(me too) after:
http://www.SPORTPROTECTION.com