I have rock climbed in Scarpa Denalis when doing some ski traversing in Canada and it was bloody awful. They just don't have the feel and your lower leg is essentially locked down, even w/all buckles released. Downclimbing steep ice is a real pain because french technique is almost totally out. I use them for easy climbs like Leutholds and South side on hood but not much else. I have put in some practice with mountaineering boots in skis, so I prefer to sacrifice skiing speed for good climbing. The plastics in AT boots tends to be much stiffer than that of plastic mountaineering boots. Maybe there are better AT climbing boots out there. Denalis are definitely geared for the skier. The Scarpa F1 intrigues me, but I wonder if it is any better than my Invernos. I have climbed with many people who climb w/ tele boots successfully, but I've also heard a lot of bitching about them too. Both AT and tele boots take crampons, but obviously model compat. should be confirmed.