Lots of great input here. It's funny, when I was thinking about some of the hikes I've taken, with significant elevation change, I am sure that I've had stretches where instead of miles per hour, I'd be looking at hours per mile! The Mahoosic Notch section of the AT in western Maine comes to mind. Anyone else ever traverse that mile? I gotta dig up some pictures.

A trail I've done at least a half dozen times, roundtrip from Pinkham Notch center via Tuckerman's Ravine trail to summit of Washington. (Sometimes I go up Lions Head, and down Tuck) From the Pinkham Notch visitors center, it's about 4300 ft elevation gain to the 6288 summit. The trail is only 8.4 miles, but, it's typically an 8 hour round trip, about 1mph. The guidebook says it should take 6:20, but, I guess I'm not in that kind of shape, or pack too much stuff. Don't always keep track of top time hanging out either, especially if it's a nice day. (Nice means above freezing, in summer)