The MTM model does have a rear support - the ramp at the tail, as does the Bog-gear (both are pictured). But they both offer accommodating dimension for the rear bag, which the Pistolero rest you've pictured really doesn't, not without getting you a foot off of the bench.

The downside to the Caldwell Pistolero SuperHunt pictured (which I also own), is the rear support is too stiff AND too tall. Gets you WAY up off of the bench, then that box is way too stiff - putting a rear bag on top, it gets even taller. I like to rest my elbows on the bench to support myself, then have my forearms level and arms almost straight. The slanted body of the MTM lets me stick in a rear bag a lot easier than the Pistolero.

Take the box off of the Pistolero and you end up with nothing more than a standard front rest, complete with all of the same problems, and a whole lot MORE problems.