Is he going 2-3 hours by his choice? If he's gaining weight and isn't ready to eat before then, I'd say you're doing fine. I'm a bit of an overproducer myself and I couldn't believe that DS could be done eating so quickly, especially when everything says a feeding should take 30 minutes! But he hardly ever stays on the breast past 10 minutes and his weight is fine.
Some questions for you--when you first put your baby on does he cough/choke/sputter? If he pops off the breast do you have to quickly cover up your nipple or end up squirting him in the face? When you pump do you get 3 or 4 ounces out within 10 or 15 minutes?
If the answers are yes than you just have a fast letdown and make a lot of milk. You're doing just fine.

Oh yeah, and he might wake up 2 to 3 times a night for a while yet. Try dreamfeeding and you might get a good 5 or 6 hour stretch out of him.