In reply to jethro kiernan:
Hoka speedgoats are excellent on rough trails.
The Hoka Challenger Airs are the most comfortable running shoes I have ever owned, but the soles aren't up to serious terrain - they just fall apart.
I've previously taken a pair of Hokas and had LSR retrofit them with a fell sole. I've not done it with the Challenger Airs, but i see no reason why it wouldn't work.
The LSR fell sole is ridiculous. Once you get them back, wear them round town for a week or so to get the studs worn down to a reasonable level. Then they will be just perfect
Steve