Saying that the combat is slow is a bit of a misconception. The animation is definitely slow, like how long it takes for characters to recover from being knocked down, and of course how slow everyone "runs" when weapons are drawn, which is something they brought back for Inquisition but the latter is a bit faster paced. At the very least, the slow recovery is the same for everyone, even enemies. It's only really a problem at the lower levels when you haven't turned your characters into a group of walking fortresses with high resistances, but it's made worse on the console, because melee characters love to charge off on their own and die, and your only recourse to prevent that is hold position, which at least frikkin works in this game.
But as for the combat itself, once you're way up there and spec'd right, wiping out enemies can become kind of a breeze, and despite the slow animation, battles can be over in no time. Most regular enemies basically become XP tokens for you to nab. As for the ridiculous animation in the other games, I never really considered them any more so than that acrobatics move you do when you kill a dragon.
That being said, I consider Origins' mages to be pretty boring. I can't really stand to go through the whole game playing as one, and prefer to just use the spells of my allies to my advantage while I play a rogue. The same is kind of true for archers for me as well. Say what one will of Inquisition, but I can finally play an archer and actually enjoy it, much like DA2 was where I finally learned to enjoy the mage, though screw Carver.