RPT, I stopped doing mass start road and track races in 2010. I became a specialist and do track time trials and track team events. I may do a road time trial or hill climb if it compliments my training.
As far as camaraderie with other racers, I think the track offers more than road. Part of it is the small venue that facilitates racers getting to know each other. Having said that, some tracks are more congenial and friendly than others.