Blue
Ravenous Bugblatter Beast of Traal
We played 4e on a weeknight, and when we got to mid paragon the average combat was lasting more than a full session.So this is the interesting thing -- for me, the actual time does not make a difference. It really is the rounds.
So, for example, I play D&D 4E because I love the team-based tactical combat.
The time spent was ridiculous. It took over so badly that it prevented fun. So it was really about time for us.
We had a typical group of gamers, not a tactical live-for-combat wargamers. One players needed to reevaluate all of their available options every round, another recalculated the math every attack (okay, I get +4 to hit from my strength, and +2 from my weapons, and ...), and with 30-45 minutes between actions everyone would space out during it and then end up with frequent recaps of "which one is hurt" and "what conditions do they have on them".
By having lots of unique powers per character, it entered a death spiral where even one player with option paralysis slowed everything down so that combat lost all momentum. In other editions those would be the players that didn't pick spellcasters.
But regardless of the game, 20-30 minutes for a scene is all we need. Not an excuse that "well, *this* scene will supplant several other scenes because it wooooo combat!"