Dutch,
I held off for a long time to get one of the un-ported GGs. Last September, I was in the gun shop and they had a ported version that had the prettiest wood on it that I've ever seen on a Marlin, so I snatched it up. For the record, I've never shot an un-ported GG.
I killed two deer with the gun this year, and didn't notice the noise. That doesn't mean that it wasn't loud on my eardrums, but I didn't notice it at the time I fired, nor did I notice any ringing in my ears afterwards.
The load I shoot for deer, however, is far below any kind of max load. My load sends the bullet out of the barrel at 1150 fps using IMR 3031. Although this could be considered a light load, a 405 grain bullet leaving the muzzle at this velocity will consistantly kill deer out to 100 yards (and probably beyond.) Being below the max load, I'm sure it's below max volume.
I am not sorry that I have the ported version, and there's so much that's good about the gun that the ports/no ports issue pales in comparison. However, if I had it to do over again, and there were two guns available (one ported and one non-ported), I'd go for the non-ported version.
You ort to see the wood on that GG that resides in my closet! It's downright beautiful!
Someone has posted in the past about the effeciency of ports vs. velocity, and according to him, the effect of ports is quite minimal at the velocities at which large bullets are fired from a 45/70. See if you can hail him on this topic...he'll give you a pagefull of entertainment!
The Blade