Thinking about buying my first suppressor. Looking at the Sparrow vs. the Switchback.
Allow me to suggest a slightly different track.
Get a can rated for 5.7x28 instead. Then it can handle .22LR, .22mag AND 5.7 without changing anything. Price is not much higher than a straight .22LR can & 10 times more versatile.
Another train of thought is looking at a 5.56 can. It will easily handle any caliber below it as long as it's in the .22 diameter. The downside is, it'll probably cost 2X as much as a 5.7 can. Certainly 2X as a dedicated .22 can. But the upside is you can use it on your ARs.
I have made every mistake possible in buying my early couple of cans. In short, I didn't do my homework beforehand. Hard lessons learned.
I always look at dB reduction rating first. Much like we look at horsepower on a car first, IMO. Some mfgrs list theirs, some don't. However, there are a lot of web sites of guys who list those sorts of things as a comparison. Some are video, some are written. I prefer the written ones myself, YMMV.
When it comes to finally buying one, look for a shop that has an electronic kiosk for fingerprints. Makes life a LOT easier on the buying process. Not all Class 3 shops are equal either, FWIW. Don't be afraid to shop around before you buy.
Thank about a NFA trust as well. This allows you to add or remove names of people who are allowed to possess the can. There're several web sites that explain the process much better than I do.
In short, I use three criteria: noise reduction, ease of cleaning & price. I want the best possible combo when I spend my $$$.
My .o2