If you drive on the road don't go for the bias's. The Irok's do not do as well in the mud as TSL's they are better on rocks. TRXUS MT have the best manners all around. Still a good mud tire, but they last well on the road and do great in snow and ice. One of the best ice tires I have ever driven. One of the guys I wheel with weekend warriors his on rocks and they grip as good as any MT. If you are wanting a pure mud tire a bias bogger is about as good as it gets. They will wear quick as hell though. Balance wise you could get a radial set of TSL's but you loose a lot if the heavy sidelug that makes it a better mud tire going to radials.
here they all are side by side
the bias tires have a lot more bite to them. In all honesty I don't think the radial TSL is worth it over the TRXUS MT you gain way to much in all around performance for the slight loss in mud. I personally wheel on a set of bias 33x12.50R15 TSL's and they get the hell beat out of them, they don't last for shit.