I hike several days a week all year in rough mountain terrain, much of it off-trail and over rocks.  I've gone through several pairs of these Hi-Tec Altitude boots over the years.  The factory supplied insoles are comfortable initially, but are made of a compressible closed cell foam that eventually does not rebound from compression well after some months of use.  When the foam becomes compressed, the padded effect is lost and my feet begin to hurt.  This can be solved by purchasing and installing an aftermarket pair of insoles such as the Sole Softec Ultra foodbeds, or another quality insole.

This problem is not exclusive to Hi-Tec, as I've seen it with other boots and running shoes also.  Some aftermarket insoles/footbeds are made of resilient material that does not tend to stay compressed with heavy use.  I am not sure why the manufacturers of boots and shoes don't just use suitable footbeds in the first place, but I assume that they save a little money by doing what they do.

Aside from the poor insoles, the boots themselves are comfortable, keep my feet warm in fairly cold weather even though they are not insulated, and the soles provide good traction.

UPDATE 2-26-2012

My son purchased a pair of these Hi Tec Altitude boots in the last year.  After only 100 miles of hiking, the traction lugs on the soles were deteriorating very badly and coming off.  Suspect a bad batch of the sole composite material.  I purchased some of the very first Hi Tec boots when they first came out and they held up very well.  Then, some years ago, our family had backpacked twelve miles into a designated wilderness and the sole of my daughter's Hi Tec boot completely separated from the upper.  Lacking any repair material, I had to hike 12 miles out, drive to town several hours away, purchase a new pair of boots, drive back, and hike twelve miles back in with the new non-Hi Tec boots, just in time to join the family on a 12 mile hike out!  I'd assumed that perhaps in the years that passed, Hi Tec had solved the quality control issues, that the experience was a fluke, and I went back to them.  A mistake, apparently.