I've ran just about every type of Super Swamper tire out there at one time or another.
Boggers: Purpose built tire for mud. Work OK on the rocks but need grooving to help with side hills and slipping.
TSL's and SX's: Great tires, with grooving a really great tire. Problem I have with them, the side walls are thick but soft, so they do cut easier than other types of Super Swampers.
Thornbirds: STAY AWAY, some people like them, and for an AT tire, they're OK, but not my choice by a long shot.
Iroks: Best all around tire that Super Swamper has produced that I've used. Great overall traction, and the rubber in the side walls seems to be slightly tougher than other Swampers. Don't ask me why, but it's the only style that I haven't cut a sidewall with.
I don't run and have no experience with many of the radials. If Swamper had a choice between bias and radial in the type I wanted, then I always went bias, even for my daily driver. And YES, the Bogger will have a slightly deeper tread, but the rubber will wear off 10x's faster. Plus the road noise really sucks.
My vote is with the bias Irok's.