Seat time? As in saddle time? I never broke 1000 miles in a month, but came close several times. My commuter miles probably pushed me over, but I never counted them.

Definitely got faster, and more fluid/efficient on the road. Despite running out of water and weighing 180 pounds, I was the chubbiest guy at the l'Etape du California finish line, then found out later I'd finished 146th of 955 finishers, out of 1600+ entrants. (And that Dave Zabriskie had finished 25th.) No way I could've managed that with my previous choppy spin.