I have a set 325/60/20 with about 22k on them and probably need to replace them in about another 5k and i have a heavy foot. I also have been rotating them every 5k too. They ride nice and were quiet but seem to be getting a little bit louder as there are wearing down but could be in my head too. I think they are a good on road tire and light off-roading but there are too many times I think I should of been able to make it in 2wd but had to put it in 4wd. The other issue I have is in this size they only offer a D load rating and a max psi of 50.
2006 GMC Sierra 2500HD 4wd CCSB
6-8" CST lift w/ King shocks,
325/60/20 Nitto Terra Grappler on 20" XD monster wheel
EFILive tuned ecm by Idahorob dsp5
5" Flo-Pro straight exhaust
EGR block plate