Slightly, as in you probably need a decibel meter to really see a difference, because it's very hard to hear one unless you are doing a side by side comparison.
I do the same thing with a Thunder Beast Ultra 9CB, .30 cal can, and run it from .223 to .300 WM. Personally, $1,300 all in is a lot to spend on a "shooting accessory", so I don't need multiples. This .30 cal does it all and under 12oz.
I will tell you different. I would tell you NOT to go with Elite Iron or a full auto can unless you are actually shooting full auto, or plan on helo-casting in full battledress with your suppressor mounted. They are certainly tougher by a mile, no question, but they're also as much as 4X the weight. I'm a big guy and I don't mind heavy rifles AT ALL, but I do get annoyed when the balance is thrown way off. Not that I shoot my comp rifles off hand much, but I hunt suppressed too. I find the Elite Iron and full auto suppressors are just too darn heavy relative to their position on the end of the barrel. Hang a 4-5 lb weight on the end of your barrel and see how much fun it is to try and tote/shoot it. It's fine fully supported, and all that weight actually helps give you more control full auto, but it's not great on a bolt gun IMO. I get annoyed by it. Maybe you won't, or you are actually planning on driving a car over your can and need it to be THAT tough, but I pretty much baby mine. The worst I do is jamb the end of it into a 2X4 on a barricade because I'm rushing. The rest of the time I'm pretty careful with it, and although it's light it's still pretty tough...
Most competitors run the 7" in competition, because they're even lighter, and easier to maneuver (like stick through a barricade hole). There are some really good, short ones out there. I run a that 9" (I don't see many long ones at matches). It IS harder to maneuver the rifle on certain stages, and I've wished I got a shorter one on occasion, but because I run it on so many different calibers I've found that on the magnums (maybe only on the magnums) the longer ones are significantly quieter and have better recoil mitigation (manufacturers claims withstanding). If recoil isn't an issue you don't need such a long one.
If money were no object I would have short 6 and 6.5mm cans as well, but I have to say that I am 100% satisfied with the Thunderbeast .30 as a do it all can that makes everything hearing safe. The only knock would be the length, but I chose that knowing it would be an issue in some of the shooting I do, and it was a conscious compromise because I love shooting it on my .300WM as well.