As long as the yeast is healthy (not stressed by too low a pitching rate, high temps, low temps, etc) it doesn't matter. It takes however long it takes. Sometimes a fast and furious ferment is the result of high temperatures and that's an issue. Yeast do love warmer temperatures, but it can cause off-flavors in the beer. If the temperature was in the desired range, though, and the correct amount of yeast was pitched, it's all fine.
I've had a beer in primary for about 2 1/2 or three weeks now. I assume it's done and been done for a while but whether it took 2 days or 2 weeks, I have no idea. I'll check the SG before I go to rack it to make sure it's finished, but otherwise I haven't even looked at it.