I think people using Hincapie's climbing results as reasons for doping are a bit off the mark. Hincapie won one mountain stage in the tour... from a break. Let's not think he somehow "outclimbed" guys like Ulrich, Armstrong and Basso. Rather he outclimbed Pereiro, Cauchiolli and Boogerd. It's a bit different animal. He also finished 13 minutes back in the mountain stage the day before... possibly saving energy for an attempt at a breakaway stage win.
If anything, his exploits in terms of dropping people from the pack weren't any different then what Cancellera has done the last couple of years... high tempo at the base of a mountain to drop some people. Then guys like Heras, Landis, Acevedo or Salvoldelli would keep the pace up to continue dropping people. Cancellera dropped Sastre from the pelaton in the tour this year too.
Hincapie was never a great climber. He was adequate, but that was about all. Maybe he got to adequate by doping, maybe not... but even at his best climbing years he'd finish near guys like Gilbert more often then guys like Ulrich. In 2006 in the first mountain stage... presumably with the support of the discovery channel team as a GC threat... he finished 46th... 21 minutes down to Landis, Leipheimer and Menchov. His climbing was on par with Botcharov and Lefervre.
It's different to kill yourself at the base of a climb to weed out the pelaton for a team leader and try to hang with the climbers up a whole climb. Hincapie could do the former... just like Cancellera can now. He could NEVER do the latter. His climbing prowess was never that far out of the norm for the larger guys with big engines and a bit of staying power.