Well, comparing it to a Polonium (5.56 suppressor) that's a duty-rated 5.56 can made of 17-4 stainless (totally different material) is not even an apples to oranges, it's like comparing a watermelon to a peanut. They're just too dissimilar to compare. Yes, they're both suppressors, but that's where the similarities ends. I wouldn't use those 2 as a comparison in the future.
The Hydrogen-S 7.62 (I have one of these, too) will have more noticeable recoil and be louder than the Magnus...It is 2" shorter, and nearly 0.200" smaller in diameter. The Hydro-S 7.62 would be better compared to an Ultra 7 Gen2. Comparing the Magnus to the Hydro-S is comparing apples to bananas. Once again, dissimilar comparison, so not really fair to compare it. The Magnus would be more inclined to be compared to a Hydrogen-L 7.62...Of which I also have.
Yes, the Magnus will be gassy on an AR, as it's designed for maximum suppression and traps more gasses than a can built to be shot on a semi-auto. It is not a flow-through or low back pressure design. It was more designed to be a bolt-action or single-shot precision rifle/hunting can for people who want maximum decibel reduction.