As I've said (and I notice you've not taken into account) its not "roll, hit/miss, damage, repeat" that is slowing down combat, its mass-bull-strengthed, enlarged, polymorphed, hasted PCs making full attacks with 2-handed power attack while their summoned monsters move into flank and make full attacks, and oh, did I mention I have a quickened fireball?
+4 Strength (+2 damage, +2 to hit)
+2 Strength (+1 damage, +1 to hit), -2 Dex (-1 AC, -1 Reflex), -1 to hit, -1 AC; increase size category (reach)
+1 attack, +1 AC, +1 Reflex; 1 extra attack on full attack
2-handed power attack = -X to hit, +2X to damage
I timed myself on the rule look-ups and the math. The polymorph depends on what you're shifting into, but that's just a matter of swapping ability scores. It took me four minutes.
So even if ALL OF THAT was done to me in a single round and I hadn't bothered to either look up the spells as they were being cast or to note the changes as they were happening instead of waiting until my turn to figure out what my stat block looked like... Well, I'm still not quite figuring out where the 10-15 minute turn is supposed to be coming from.
It surely can't take you that long to roll dice, can it?
(And surely you're not re-calculating your stats every time you roll them, instead of actually keeping track of them? I can see how that kind of silliness would waste a lot of time. But it makes about as much sense as keeping separate track of every wound you've sustained and then adding them all up every time you get hit again to see if you're going down or not.)
In short, make combat more like 4e.![]()
During our playtests we found 4E combats to be incredibly tedious. Fewer meaningful options, less powerful attacks, and enemies with more hit points all added up to longer and more boring combat.
I can see how it might save resolution time if you're of the "I need to recalculate my combat bonuses every time I roll an attack" school of play, but for us the fact that 50% of combats ended in tedium was one of the major turn-offs of 4E play.
"Padded sumo wrestling" was pretty much our experience.