The one I'd rather watch is the 10 girls on 1 guy reverse gangbang.
However, I really wouldn't want to watch either, because with that many people and so much happening the camera won't stay in one place very long and you can't see much, the girl can really only service 7 guys at the time leaving 3 to take care of themselves as they rotate around, and while you can gut 8 girls on the guy and the other two can take care of themselves or lez it up with the others, there's still too much going on for just one viewing angle from 1 camera at the time.