I've seen what the 20gauge can do with the heavyweight #7's and what some pards with the TSS, which is my next go.
No injuries, of course age always factors on everything, but a 20 gauge is all one needs with the right ammo.
There is no reason to lug around a shotgun that weighs a few more pounds and beats the sheit out of you. Recoil really isn't a big issue, since you seldom shoot.
So in short, you aren't gaining anything with the 12 gauge.