I've ran Boggers, TSLs, SSRs, and SXs. IMO, the SX is the best of the bunch. It's a little like the Bogger in that they do well on a somewhat heavier rig and/or with beadlocks. That allows you to get them to belly-out and really hook up. The SX shoulder lugs are slightly smaller than the TSL, but the sidewall tread makes up for it once you're in the ruts. I've only wheeled the SSRs twice, but they do hook-up well. As a radial the lugs are smaller and more tightly spaced, but still one of the most aggressive radials out there. For overall wheeling, I'd rate them in this order:
SX
TSL
SSR
Bogger
Of course, depending on the terrain you wheel the most, you may disagree.