If I were buying a new .22 can I would look for three things.
1 All stainless steel construction. This would make the can safe to use in “the dip” as well as in an ultrasonic cleaner.
2 Monocore consturcion. I like monocore since there is no need to line up baffles in the correct orientation or mess with anything like that. Also K baffles (non-monocore) which are the most common these days can be fragile when outside of the can for cleaning.
3 Sound. This would be my lowest priority since nearly all these cans offer outstanding performance. I wouldn’t buy a loud can but if I could have one that was 1 or 2 db louder which offered the features above I would go with that one.
I would probably look at Liberty suppressors if I wanted another .22lr can. Their Kodiak looks amazing. I have not heard it in person but have heard all the other cans people have listed here today and it looks to be right in the mix sound wise. The can has only three parts and indestructible. Also good for use on .22 hornet and .22 magnum.
http://www.libertycans.net/kodiak.html
If you really want to see some sound data get a membership to “Silencer Research” they do independent suppressor testing. Never trust the db numbers a manufacturer gives you.
I would probably think that any modern muzzle can would blow the High Standard HDM out of the water. The AWC Amphibian uses a ported barrel which brings the velocity way down; much slower than is necessary. Also neither of these can be cleaned. When they fill up with carbon and led deposits they get loud and you have to send them back to the manufacturer. I like to do my own maintenance.
Dan