I also prefer my IPAs as soon as I can get them kegged and (mostly) carbed. My usual pattern for them is two weeks in the primary, then a week of lots of dry hopping, then into the fridge it goes. I usually give them a bit of a shake to help speed up the carbing, but it's only a few days before I start drinking them, and I think they hit the peak at about a month after the brew day and start to fade from there.
I do my IPAs in a definite west coast style, with lots of late hop additions. My experience has been that after about 2 or 3 months, they're still pretty good, but missing that "something" that makes them really spectacular before.