Definitely fast and slow boats, probably some in between. Some generalizations, which means there are probably exceptions ...
Smaller boats, faster. Bigger boats, slower.
Smaller boats, fewer people. Bigger boats, more people.
Smaller boats, less space. Bigger boats, maybe more space.
Smaller boats, less shade. Bigger boats, more shade.
Smaller boats, probably no head. Bigger boats, maybe yes, a head.
Smaller boats, your seat is your seat. Bigger boats, maybe you move around and lounge a little.
Smaller (faster) boats, first to the dive sites, with a shorter ride, but maybe a rough ride on certain days. Bigger boats, slower to the dive sites, but maybe a cushier ride.
Again, these are ALL GENERALIZATIONS, so you will probably hear from a lot of folks who dive with ops whose boats are the "exception to the rule". And, as you can probably imagine, there are enough different kinds of divers in Coz that every type of boat is the favorite of a certain group.