The main determinant for fun in versus is how balanced the levels are. You frequently get completely unbalanced teams in terms of versus rank. It shouldn’t be too hard for the game to sort out players into different teams depending on their rank. Alternatively, there should be a mechanism for changing teams at any time with the approval of the player that you are switching teams with.
Mostly it depends on player time. Most newbies with high ranks are stiil very bad as heroes.
They seem completely unbalanced in all regards. Last game I played was my team (four 35s) against a group of four ranging between level 5 and level 21. Needless to say we stomped them into the ground every round.
I’m assuming that since the difficulty level is set so low (Recruit right?) the levels don’t matter in terms of hero power (dmg/stagger etc), but those levels are a pretty good proxy for player skill.