I've read that somewhere before too. I guess it was one of those 'gun writing experts' saying it. Personally I shot '06 that smacked you pretty good and others that were just love taps with the same load. A lot has to do with the stock design. I despised pattering my 870 Super mag with 3 1/2" turkey loads from the bench. That gave me one heck of a headache - literally.
The largest rifle I've ever fired was a 460WM. I shot that one off hand and it seemed like it turned my upper body 90 degrees with the recoil. Right now the hardest kicking rifles I have are my Browning Micro hunter in 325WSM and my Marlin Guide gun 45-70. The 2 rifles are light and let you know when they went off but the recoil is by no means intolerable.
What I would REALLY love to shoot would be a nice double rifle in 500NE.