I wish round-based spawn system would be removed, almost entirely, in favor of the capture-and-hold flag system + wave-based respawn system of Day of Defeat. I'm totally baffled as to how people can find round-based spawn system the ideal way to go. It seems mathematically flawed, forcing a majority of players to spend up to 50% of their logged game time in "dead observer" mode. I've played both modes in many games very much, and I see no tactical/strategical scenarios that come up in round-based that wave-based doesn't provide just as well. In DOD, players behave exactly like their round-based counterparts. They fear death, they take cover, they work together.
in counter-terrorism games like Rainbow and CS, it makes sense. But it definately stops making sense when either game type has you in a MASSIVE level where 2 players can spend 5 minutes hunting each other down.. (see America's Army... aka "chatroom w/ game attached to it")
Day of Defeat introduced a round-based system, even on small CS-like maps it was not a popular feature. The game kicked round-based out entirely in the latest version, and no one missed it. CS, America's Army, and Rainbow Six, on the other hand, have never tried to implement a wave-based system...... and I think that if they did, along with suitable maps and capture-and-hold gameplay... that most of their fanbase would never go back to round-based.