I've been running grooved 38.5 sx's and can't be happier with their performance offroad, and can stand the shake and wobbles that are typical with sx's. I drive my truck around 9000 miles a year, with an even mix of offroad, driving to the trail and a bit of DD. Half the year I wheel in vegas and moab, typical rockcrawling and the other half I'm in mud, dirt, and snow up in Idaho.
It's time for new tires and am still deciding between 37" pitbull rockers and 37 14.50 , 38 13.00 , 37 12.50 maxis creepy crawlers (because I can any of them through work at a decent price). I've pretty much ruled out Iroks because of chunking and tire wear. I'm looking to get two years of use out of this next set.
I've seen the pitbulls on the trail and are very impressed with their performance but have heard conflicting results on tire wear. I have almost no experience with the Creepy Crawlers on or off road. It looks like the Maxis tires have a much higher weight rating in the 37"+ sizes, and don't know how that will affect performance.
For those of you with personal experience with either of these tires, please post up your impressions both on and offroad including tire wear and sidewall durability.