Curious whether anyone has had experience with the new line of Sig suppressors. The way they write about it, it's the best thing to hit rifles in 200 years.

There is some info regarding the new SL and SX cans on TFB under the Silencer Saturday tab. It is a while back though and not very specific. Also Pew Science did a recent test which is more definitive. It appears that the SL7.62 version is not as quiet as the older version but this is probably due to the lower back pressure design. You don't get something for nothing. I suspect to get the same sound suppression from the reduced back pressure cans they would need to have much more internal volume to contain the gas and give it time to dissipate.

I spoke with a Sig rep about them, not long after their "release". I inquired, mainly, about their misleading and dishonest marketing, which he did concede was not an objective performance illustration. I think the whole flow-through thing is a bit overblown. When the main talking point became "operator health" instead of weapon function and cleanliness, it started to feel gimmicky. I have mentioned before, something I read in an interview with Karl Brugger (B&T), concerning low pressure cans (the RBS, in the case of B&T): he said that high-speed military users purchase RBS cans for training, but take conventional (Rotex) cans on the deployment. He said things like cleanliness and "operator health" are perks in the training environment, but ultimate signature reduction is the priority in the real world. Now, I am not a "real world" employer of silencers, in the military sense, so perhaps I should care more about low-pressure designs, but I don't. I use a silencer all the time, and I tweak the gun to mitigate it's negative effects. It's a full-time part of the system, so I don't care about how it runs without it, and emissions are greatly reduced when the weapon is "tuned" for silencer use.

Reduced pressure designs apparently have three applications: 1)A case in which the host weapon is required to function with and without the silencer with little to no "adjustment". 2)A training environment. 3) A case in which the host weapon can't be tweaked to enable good function with a conventional silencer.

I am likely overlooking something, but that's my general observation on the matter. I have an OSS HXQD 5.56 silencer; I use it on my TG36C; I have no intention of using it on anything else. It suits that gun, as there isn't much you can do to otherwise tweak the system, and it most definitely runs cleaner than a conventional can on the same gun. I guess the low pressure designs could be considered a boon to certain specific applications, but not necessarily "all-around better" than conventional designs.

I came from the Soviet State of Illinois, where gun ownership in general is rather frowned upon. Cans and SBR's are definite NO-NO's.Even 30-round AR's no longer have official "sanction". So now that I live in Texas, I am working on getting some of those things. My hearing is shot so anything that reduces sound signature is welcome.

I am interested in a couple cans. I would love to have one for .22, for 9mm, for .45 ACP, for 5.56, and for a .300 BLK I plan on building as an SBR.

Problem is, I just don't know where to get solid advise about what to consider. I read the Sig announcement, but obviously Sig is more Show than Go. Don't rightly know where to get good info.

There are an incredible number of places that review suppressors and give you data. For real info I like Pew Science but the scope of their work is necessarily limited. And of course you can go to sigforum for help as well. I am unclear if you are asking if people have advice for you solely on SIG as the sole supplier for your needs (because I can't help you on that, I wouldn't buy one of their cans) but you can easily get a consensus on certain other choices that are good starting points for example...
.22 dead air mask
9mm dead air wolfman
45 Rugged Obsidian 45
5.56 Surefire rc2 or sb2
300 blk dead air nomad or my favorite the Surefire 300sps.

Of course once I post this you will get dozens and dozens of different recommendations, but mostly they will (like my list) be from Sigforum people who have actual experience. The reason for the various options is that there are tradeoffs in this space and money, sound reduction, size, weight, mount etc. all matter in the concept of what's best for your needs.
But I can guarantee that if you get my list you will be a happy person in however many months the ATF takes to process it. But I'm sure we will have a bunch of alternative lists shortly. But it will give you some bounds on the things you can go research especially if the posts are about actual personal experience and not internet shopping...