I had the 30x10.50 Cooper STT mud terrain on my Tracker. I let my alignment get a little out of control, prematurely wearing the fronts, but the backs still had about 9/32(Lots of tread) tread after approximately 70,000 kms (44,000 miles). Great tire. A couple years ago Cooper changed their design and put the nobby sidewalls on em. They look nice. I would buy them again!
PS I only got stuck in mud twice with them. Both times the distributor got wet and stalled out. If I could have kept the tires spinning, I'm sure I could say I was never stuck in mud. Also, there not so good on ice. (no siping)