I haven't had an opportunity to shoot the RB in .454 but I do own the .500 Magnum model with the 10" barrel. While the recoil is there and it certainly does get your attention, it's not by any means unmanageable. The weight coupled with the ribber grips and the porting all go a long way towards reducing felt recoil.
To me, I perceive the .500 as more of a backwards shove into the palm of my hand rather than a sharp muzzle flip, associated with some big bore revolvers.
Congrats too on your purchase.