Rich,
Yes I do know this, and how I learned it was learning it the hard way as a young bulletproof inexperienced pilot! A Cherokee Six with 4 on board, lots of bags and full fuel will cross the end of an 8000' long runway at Denver Front Range at about 20' and spend some more time in ground effect beyond the fence, all this on an 80 degree day! Once it started up hill I was lucky to get about 250 fpm, and really had trouble outclimbing the very weak downdrafts. I survived and decided I should learn more than just a cursery mention of density altitude that I had been left with out of my flight training. Since then, and with considerable mountain flying experience in a variety of light aircraft, some tuboed, some not, I can definitively say that some do better than others! Comanches and Mooneys, with their laminar flow wings are the best. The Hershey Bar winged Pipers are the worst, regardless of how much horsepower, and everything else is somewhere in between. Every time I get my Comanche 180 to high country, it still amazes me with its performance from such relatively low horsepower. My turbo Twinkie in Leadville is fine too, as long as you can figure out how to keep the engines running long enough to get to the runway
Rich has a point that I will make also. Lots of experience with flat lands does not prepare you for the high country, and density altitude is real, it bears watching, and things are different in the hills. Get a competent checkout before attempting any mountain flying. What you do have going for you here is that the Comanche is one of the best hot/high light aircraft that you can fly, but it still needs to be respected in both takeoff distance as well as climb gradient.
Now back to forum performance...must be some serious density altitude issues with the server...
-Zach