ime, there are plenty of lower cost rings that will hold zero just as well. i've had good luck with seekins, talley, vortex, badger and others. The reason I got a spuhr mount was to attach an IR illuminator and IR laser to the scope. the Illuminator works fine hung off an EFR mount, but the laser will not hold a zero because of the flex in the forearm of the stock. (literally, loading the bipod will cause the EFR attached laser to move more than 1 mil relative to the crosshairs in the scope.)
the integral bubble level is cool, but a $12 b-square level attached to the rail works a little better for me (i'm left handed).
the angled leveling piece is pretty dang handy, but a cheap set of feeler gauges work too.