I have both the 577 3" and various 450-470s. The recoil in the 577 is quite a bit more than the others. My 577 originally weighed in at 10.5lbs but now weighs 13lbs.

Stopping power is quite a bit different also.

I actually prefer the 577 2 3/4 with the 750 grain bullet. I believe it is much closer to the 500 in recoil and energy but does have the much larger bullet.