No real contribution to make to this discussion other than to relate my experience of both. I have used 450 NE often enough (not mine, I have a 450/400) and while I sure would not want to shoot it all day it is ok. A bloke here has a break action (H&R possibly?) 45/120 that is super light, and he loads it up there. When I first saw him using it I was amused to see and hear him groaning and flexing his shoulder after every shot (this on a Group 2 BGR shoot) and let him know about it. Then he handed it to me and I used it for the same course of shooting. I will never seek to own and use one and I will never again offer anything but sympathy to him, good god it was brutal.

Alex