I wouldn't worry about class size. If they run it right you'll be rolling with lot's of different people and that's a good thing. If what they say is true, and you dominate your belt level, you'll get moved up quickly.
1 hour is too short though. Do they offer longer classes for more advanced students? I could see running just one hour for like white belts to introduce them to the discipline and get their stamina built up. But, once you move past that I would think they'd give you more mat time in a single class. Are there open mat times?
good luck and have fun.
"George never did wake up. And, even all that talking didn't make death any easier...at least not for us. Maybe, in the end, all you can really hope for is that your last thought is a nice one...even if it's just about the taste of a nice cold beer."
"If you find the right balance between desperation and fear you can make people believe anything"
"Is enlightenment even possible? Or, did I drive by it like a missed exit?"
It's simpler than you think.
I could be completely wrong"