The discovery of the incline feature was a revelation to me (dooohh!) and I decided to buck up and run on the treadmill once per week for Mt. Washington 2010. I did 3 runs in the Seattle Sheraton just after new year but didn't jump back on until late February, when the snow around here became sketchy and thoughts of Mt. Washington were rising to consciousness. So I paid my $45 for 6 months membership at the USM gym which is about 50 yards from my office. And I did manage to run it 11 of the last 15 weeks.
All treadmill workouts were at 11.5% grade (Mt. Washington average grade), generally 30-45 minutes, and almost all were tempo or tempo intervals (last week's was my only easy run).
Total miles treadhill climbing: 43.72
Total feet climbed: 26,260
Avg grade: 11.4%
That's about 5.75 Mt. Washington Road Races.
I'm ready to let my membership expire until next spring (treadmill running is boring).