I was running 31x10.5x15 MTZ's on my TD hilux, and found them really good. On road grip is fantastic, either wet or dry- Could push harder than the vehicle was really capable of and they still didnt let go! (felt like the lux was going to fall over!)
offroad i found them very versatile- in sand i had to drop to around 8psi to get myself off a nasty beach- but that beach also involved about 2hrs winching to get an 80 series and GQ off it too! Normally run around 12-14psi in them on the sand and they go everywhere i want them too.
In mud they are good until you hit the sticky crap, then they do suffer some clogging- But nothing short of Pedes will help in that snot.
Fast gravel had a bit of vaugeness, but that could be attributed to the road pressures.
On rocks they are as good as my cousins MT/R's- never had problems with lack of grip, more lack of tyre size to get up objects!
Wear- I rotated every 10K kms, and ran them at around 34psi on an unladen hilux, took them off at 40,000kms and they were still over 50% remaining.
Reason i took them off? So i could put 285/75R16 MTZ's on!
2005 HDJ100 Manual, ARB bar, XD9000 winch, ARB rooftop tent + awning, Drawers, Engel, 2" OME lift, 285/75R16 KM2's, iCom, HID XGT's.