In reply to girlymonkey:
I use Altra Superior as my off-road shoe of choice. I have a bunion on my left foot and need the 'foot-shaped' forefoot. I also have quite narrow heels, but I find that using the additional 'heel lock' lace holes keeps them nice and snug. I find these zero-drop Altras the best shoe I've ever had for doing sketchy downhill sections - they just feel so secure. Grip has never been an issue in mud or on rocky/stony sections of the coast path (I used them for the Grizzly last year). I like the removable rock plate too - sometime you need it, sometimes you don't.
Interestingly I've just bought a pair of Topos when I went to the Running Show at the NEC - very similar in looks to the Altras, but with 6mm drop. Not tried them yet, but they seem a bit more robustly made. Time will tell.
I gave up with Inov8s - wider ones were a fairly good fit and grippy too, but as you said, they're let down by fragile uppers and poor gluing.
Maybe start by experimenting with the lacing on Altras?
N