If your rifle shoots MOA, then you might jeopardize the guns accuracy by affecting its barrel vibration. Then again, I guess the same could be true that if its accuracy is bad then this new thingy couldn't hurt - I guess.
Come to think about it, as I type this, it sounds like this thingy has an intended purpose similar to that of the BOSS - finding the right vibration level along the barrel so that you can find the right sweet spot.
I know that the BOSS really works...and I mean REALLY works. I'm not quite sure how well this Simms thingy works though. Plus, it sounds like it might affect a rifle's handling, plus it could probably move easily along the barrel and thus change it's vibration/accuracy. I haven't even seen it, so I'm just guessing here.
Zachary