I have an R30T and an R556 from when they offloaded them cheap a while back. The R30T is a good can and I use it on all the AR's, but the proprietary required muzzle device turns me off and it's heavy. You can adjust the vents up front or plug them all for no vent, so you can sort of tweak the recoil direction a little bit. The R556 I have on my primary carry AR and it'll handle some serious abuse, but sound suppression isn't as good as a Polonium as it's vented to reduce gas, which it does a pretty good job of I think but I've got nothing to compare that to so FWIW.