I give my vote to the M21 20ga. I like the looks of the gun, the reliable ST and I can shoot all the off season clay targets I want without any problems. I don't understand the pleasure anyone can find in hunting a gun that might come apart at the seams if a SuperX shell is inadvertantly used.
I assume that you are referring to damascus barrels. Well, by only purchasing low-pressure 2-1/2" loads I don't have to worry about that and I certainly don't need Super X shells to kill grouse. However, I have been known to shoot AA Trap loads out of my 1889 12 ga DH with 30" damascus barrels and I pretty much vaporize the birds. But for some reason I just can't seem to break more than 23/round though.
BTW, I shoot skeet, 5-stand, clays and anything else year round with my damascus guns and I have no fear that they will fail. But I do get a chuckle out of knowing that the other guys on my squad are cringing when I call "pull."