I've been trying to decide what suppressor to get for my 20S for a few weeks and finally made up my mind and have one on order. I was deciding between Dead Air, OSS, and SureFire. Suppressor selection is so subjective and quality test data is hard to come by. Everyone has their own requirements so mine probably differ from yours (and this may be totally irrelevant) but wanted to share in case you hadn't researched all these options.
This recent Pew Science review was the largest deciding factors in going SureFire over Dead Air. I like the quick detach on the Dead Air better than the SureFire. The deciding factor for me was the incredibly low back pressure on the SureFire SOCOM 762-RC2 with no sound penalty over a Dead Air Sandman-L (Figure 13).
Surefire SOCOM762-RC2 Silencer Test with back pressure data. Real sound signature data with the Suppression Rating from PEW Science. Hearing Safe determinations for your use case. How does it do as a 308 rifle suppressor? Can it suppress 7.62 NATO? Is it the best 308 hunting suppressor?
pewscience.com
I'm watching the PMM video as I type this but I'd imagine the SCAR can be tuned to run nearly any suppressor. I like the fact that the SureFire should not require any tuning for those times when you're running without a suppressor in addition to a host of other benefits of lower back pressure. The really interesting takeaway I haven't seen mentioned anywhere else is the SureFire performs terribly with the SureFire Warcomp flash hider. Many previous reviewers that were critical of the high SPL numbers on the SureFire suppressor were running the Warcomp so take their numbers with a grain of salt.