The whole issue of sidewall toughness has changed over time........the bar has defintely moved. When MTR's came out they were pretty tough, compared to what was out before that, and they had real good grip, compared to what was out before that. For a tire that works well on the street, for toughness, traction and overall performance, I think the MTR is still one of the best out there, if not the best.
As far as sidewall toughness, there are better tires, but none of them are nice to drive on the street. Creepies are mega tough, with good bite, but terrible on the street. Claw's are tough as nails, but the regulars don't bite and they're not too good on the street, and the comp compound can't be run on the street. Krawlers are tough and bite good, but you can't run the red labels on the street and the blue labels are average bite, and while they're tougher than MTR's many guys still cut them in the rocks. The various Swamper bias plies are tough, but who wants to run TSL's or SX's on the street, and Irok's have average bite and average sidewall toughness. Everything else out there is comperable to the MTR or worse.
I've worn out a set of 35" MTR's and a set of 37" MTR's, and in that time I cut one of them, one of the 35's. And I've run them in the rocks constantly. But, others that I run with have cut them more. Unless you have TSL's, SX's, Creepies, or bias Claw's, you're going to cut a tire now and then. It comes down mostly to good or bad luck, and to some degree how careful you are picking lines and keeping an eye out for pointy rocks.....which also many times comes down to luck.
If you drive your rig on the street, if it was me, I'd stick with the MTR's unless you're past having even halfway decent street performance and just want a tougher tire.
JMHO.
Oh, and I wouldn't be caught dead running any BFG's (other than red label Krawlers), I've cut so many of them that they'll never be on one of my rigs again.