I have a Rex Silentium MG7(.358 bore diameter) and a Socom RC1 I run on 11.5 and 12.5 guns. I have a 4 baffle MGX from Rex in jail right now. The REX cans are 1.7" wide so a little fatter than normal, and I really like the look.
My MG7 bored at .358 is quieter on my 11.5 than the SOCOM RC1 is on my 12.5. This is, of course, my own perception, I don't have testing equipment, but it was noticeable to me. The tone is also more like a "psshhh" and less like a pop.
The guys at REX said my incoming 4 baffle (bored at .224) will be quieter than my RC1, and I wouldn't be surprised if they're right. I'm happy with the shorter cans.
@FuhQ does make a good point, even if I don't want to admit it, that being able to use a longer suppressor and not have to run earpro all the time is nice.
But I also didn't buy my MG7 or MG4 for that purpose. My MG7 on my 11.5 is what I personally consider just above hearing safe. Meaning I don't mind taking a shot or two in the fields or woods without earpro, even though 95% of the time I shoot I have earpro on. I won't do the same with my SOCOM, as it is more noticeably unpleasant to the ears without earpro.
That all being said, I also use these cans on all my longer barreled guns (20/18" AR's, 6.5cm bolt, 223AI bolt, .357 levergun) and for those purposes they work fine and I haven't felt I needed earpro when I shoot outside (field shooting, no structures).
I'm a fan of shorter cans, but I also understand having longer ones. I'd highly recommend looking into the
MG7 .224 Can. You can also get an MGX can and make them built to your specs with how many ever baffles you want. His MG7 standard line is 6 baffle. You can go from 3 baffle up to 18 baffle with his MGX can.