I have an Ops Inc 3rd Model and wouldn't change a thing. It's a reflex design in that almost half of the length comes back over the barrel so it only adds about 7" to the weapon even though the OAL of the suppressor is just over 12". Heavy but built for military use so it will last beyond my lifetime. 3 years now and I've shot about 25 rounds thru it. i did kill a nice 9 point in Hardin County with it on the weapon though.
When Barrett submitted their MRAD for testing in the Precision Sniper Rifle (PSR) trials, it was wearing a Thunder Beast. Surefire has a good muzzle brake attachment that has very little impact on accuracy. I've got 3 AAC cans, and I'm pretty happy with them. Prior to December, it took 5 months to get a tax stamp. I've got my fingers crossed on what's in process now.
If you want a can that will last a long time and is easier to carry, get a titanium. You'll appreciate the lighter weight if you have to carry it very far.