Running mine on a variety of calibers - 6.5 Grendel, 7mm-08 & .338 Federal. My .338 Federal (18", mid-length adj gas, with 210 gr Scirocco's) registers 131 DB's. It's ridiculous for a 20 oz can adding less than 8.5" to the rig. It's lighter and more effective that most 308 cans out there on a non-FA set up. Haven't tried it on a Lapua yet, but will very soon.
On a side note, the QD mechanism adds value not just because you have the ability to switch it from rifle to rifle, but because you have a very effective brake attached to it that gives you the benefit of the brake plus that of the suppressor itself. I had a Desert Tactical SRS in .338 LM with 26" tube and brake - that thing nearly knocks you out with the mere sound and concussion of the blast. I don't see how adding the can over a brake would improve every characteristic in that regard over a brake alone. I can see though how a direct thread would suck in terms of felt recoil compared to a brake. Time will tell....