The SSR's fave a reputation as providing very good traction. However, they are quite heavy for a radial and apparently have weak sidewalls that will slice in sharp rock. Personally I'm going with 35" MTR's but the SX's are the best off-road... tons of grip, better than Boggers and Claws on sidehills... If i was made of money I would have both MTR's and SX's
TJ- RUBI on JU rubi forum has them in the 37" variety on his Rubicon. Looks badass, no they aren't as tough as SX's, but then again, they are alot more street friendly from what I have heard than the SX.
I rode on SX's for couple years, and the flat spots, chunking and wet weather traction all sucked royally.