7v7 seems like it would be the perfect format gameplay-wise to me, because you could have your 7th always playing a utility, but I also feel like it would either be just him/her always playing heavy or it would end up as some retarded "guess what the other team is gonna run and run his counter" sort of thing : /
both teams having a 24/7 sniper could potentially speed up the stalemates because each team would have a pick class.
IDK THEORYCRAFTFORTRESS2