I've ridden with PPTC before and to answer your questions:

It's rather hard to tell the classifications because each time I've ridden with them (I'm CC), you've got B and BB riders joining the CC ride, as well. They just ride off and do their own thing. Actually everyone just kind of rode off and followed the cue sheet. However, I stayed with one guy most of the ride and then we all met back at a restaurant afterwards. Some got there early and started eating, others straggled in and sat down then ordered while the early birds were almost done, etc.
I think that's one thing that made an impression on me about PPTC ... people just took off and rode their own ride. Some may like that and others might prefer staying with a group.
Chances are you'd meet up with someone going around your pace and hang together.
This is how I see the group rides I've been on with them.

Quote Originally Posted by 7rider View Post
This sounds really interesting.
I've never done a PPTC ride before.
How true are they to the classifications and how good are they about keeping a group together?
I think I'd be a B or BB rider. I wonder if I'd (1) have a group to ride with, or (2) be dropped on the century route.