Example of the replay system. The stats board is not a bad touch.
Not that much. For some games, it just varies on your connectivity, like BB. Even with my apartment's terribad feedback, whether I'm in a match or not, there's not much lag in AH3. The instant-spectator, fast-forward addition in CS doesn't give the matches much lag either, but it does whenever someone with a bad connection just showed up. Besides, MvC3 online was bad even without spectator mode.