I am thinking about buying a 9mm but would love to hear one before I pull the trigger. If and when TP opens back up (or maybe QS one day), anyone mind letting me hear theirs? Will happily buy you a box of ammo or otherwise return the favor.

You looking for pistol can or a fixed mount can like you'd run on an Evo or MP5?

Fixed mount I can do but no pistol stuff in my collection. I do know some guys with plenty of pistol cans so I could hit them up for ya.

Fixed mount... for an Evo actually!

I've got a Bowers CAC9 with 3 lug, 5/8"X24 or 3/4"X10 end caps. The other subgun can is a GT Raptor in 40 cal but with a 9mm bushing so it fits the 9mm MP5 3 lug.
IIRC my pals have some older AAC Ti-Rants and maybe EVOs - not sure of the mounts tho.

What's your opinion on the sound? I have a rimfire suppressor and love it, but have shot friends' 5.56 and 308 cans and been unimpressed. I hear subsonic 9mm is about as close to rimfire as you can get with a centerfire.

I thinks it's worth the investment but to really enjoy suppressed shooting everyone has be shooting suppressed, tough to do that at a public range. We've been able to shoot on private property with everyone running a can and that's nice.
Subsonic 9mm will never be what 22LR is but it's probably the next best thing as you've pointed out. I reload so over the years I've come up with some pretty quiet ammo which functions in my guns.

The downside is everything gets dirty real fast! Me and my peeps often shoot FA and this exacerbates the fouling and mess. The ultrasonic cleaner gets a workout cleaning BCG's and trigger packs. The other consideration is the host itself, Uzi's, Mac's and the like don't suppress as well as the MP5 or Sig MPX. The AR15/M16 in 9mm sounds okay but the blowback action needs tuning to optimize suppressed operation, I run a hydraulic buffer which I think helps although the volume of the CAC9 can is probably the main reason. A friend in the upstate runs a 45 can on his MPX and it is very, very, very nice.

All the reports I've read on the EVO claim they make a great host even though it's a blowback action so I say go for it.

Thanks for the info. I shot you a PM too.

If any of your buddies decide to sell one of those tirants, let me know pls!

I doubt they would sell a Ti-Rant but you never know, those are still top rated cans. I'll keep you in mind.

I read up on the Bowers you mentioned and those look perfect for the Evo also. I've always like big cans (no pun intended).

I run a bowers Vers9s on a m10 and sten,
Sounds awesome on both.  Very light for the size and girth of a subgun can as well.  
The huge benefit to the subgun can on a full auto/pcc over a pistol can(even if it is FA rated) is that the gas has somewhere to go instead of back into your face.  

Of course the pcc won't send as much gas back to you as a FA, but it still makes a difference, when it's not a handgun.

IMO there is a correct tool for the job.  Subgun should get a subgun can, pistol should get a pistol can.  A PCC is a gray area, but if you do a lot of fast shooting or mag dumps, a higher volume can(subgun) will perform better.  A pistol can will be lighter, but you will deal with more gas to the face.  

As far as sound....they are probably so similar to each other that it won't matter to the ear.  I shoot a lot of 9mm FA, so even when I'm shooting with a can, I still shoot supersonic 9.
It's fine, it's suppressed, but it is not Hollywood quiet.  You get some 147 and it is just ridiculous.  That's where they shine, but it's expensive unless you reload, so keep that in mind, it's not as cost effective to shoot subsonic, so you might not do that as often.