I started shooting Keis linear comps years ago, ‘round about 2000 if I recall, and have used several Kaw Valley Precision LC’s in recent years.
I’ll point out here, baffled linear compensators and flash cans like the Fire Pig are fundamentally different in effectiveness. One is a directional letdown, one is a pressure letdown. What I’ll describe here is applicable to real linear compensators, not to flash cans. Flash cans work, kinda, to direct blast forward, at slightly lower pressure than a bare muzzle, so the indiscreet blast signature, that reaching the shooter, is lower. But the efficacy of a baffled model is much greater than that of an open can.
They’re in no way a “poor man’s suppressor,” in regards to extent of effect, but they do reduce recoil, and they do reduce total decibel release. In principle, they are a single baffle suppressor with wicked first round pop.
I did the math in another thread not so long ago (I’m on my phone, else I’d dig it up for you) revealing HOW linear compensators reduce muzzle blast, not just redirect it. BUT, they do have the added advantage of redirecting it as well. The effectiveness will be a function of the letdown volume and the cross-sectional area of the baffle ports balanced against the pressure and volume (velocity) of the escaping gases, and how much plasma remains to be unburned at the muzzle.
I’m also not a person who speaks online about items I’ve never owned or used. I’ve posted that 6.5 Grendel of mine more than too often on this forum, sporting a Kaw Valley linear compensator - I do use them. I also mentioned, after putting two shots in my buck this year, my ears were not ringing, and I did not have temporary hearing loss - which is something to which I’m quite sensitive, since unprotected gunfire has already cost me over 50% hearing loss in my left ear, and left me with the ring of tinnitus for the rest of my life.
Are they worth it? Up to you. When someone asks me if something is “worth it,” as a product developer I expect a payback, in which case there’s no financial sense in any hobby, or gear for it. If you ask, “do I feel like I get my money’s worth from them,” or “would you buy another,” then my answer is easy - yes. I use linear compensators, and I’m happy to continue buying more of them.
They don’t reduce recoil or muzzle jump as much as a radially ported brake, and they don’t reduce signature as much as a suppressor. But radially ported brakes increase blast to the shooter, and suppressors come with a lot more weight, a lot more expense, and a lot more baggage... A bit of the best of each is pretty damned good, in my book.