AbdulAlhazred
Legend
Way back in the day, I DMed AD&D durig lunch break. There was time to punch through at least one combat (with a couple of notable exceptions like a large bunch of hill giants with wolves) after some basic exploration and set-up in 40 minutes.
Multiple mundanish opponents took the longest -- bandits, orcs, etc so those got shifted to weekend play. Dragons, liches, vampires, and other very scary solitary things took between 10-30 minutes at the combat table though the player planning might take an hour or more beforehand (typically out of game time).
Dragons tended to be really fast. With luck, every PC would get a single action and then the dragon would fail its subdual chance. With really bad luck, after the first round the survivng PCs would be more worried about how to get away alive than continuing the fight.
Yeah, you guys had a quite different experience than I did. We were always playing at a table, hours at a time, with battle mats and etc. Setting up a fight took 10 minutes, the wrap up at the end was always 10 minutes, even a 10 minute fight was 30 minutes, and a 10 minute fight was pretty trivial. Anything meaningful always ended burning an hour of table time.
The other thing I remember though is, especially at low levels, there were always TONS of "one skeleton in a closet" type encounters that were basically traps, the monster jumped out, did a few points of damage, and died, THAT took 5 minutes. A small number of goblins or a couple giant spiders, centipedes, rats, etc, that stuff was all pretty quick. OTOH most of those monsters are going to be minions in 4e, or else swarms or something similar if they really are supposed to be threatening. 4 decrepit skeletons jumping out and whacking at the guy who opened up their crypt will take 5 mins in ANY system.