I love my Taurus Raging Bull in .454 Casull. I have shot the Ruger and did not think that it was as fun to shoot as the recoil was a bit more, but not too bad. I haven't shot the Super Redhawk, but if it isn't factory ported you had better plan on having it done and adding in the cost.
I think any .454 pistol should be ported and don't really plan on shooting it that much. About 50 rounds is all I can take in one day. Yes you can shoot the .45 Colt, but after I spent the better part of an hour cleaning out the cylinder after shooting some of the Winchester .45 Colt ammo, I think I will pass on doing it again. I got the gun to shoot the .454 because I think it is a blast.
I have also shot a 1 1/2", 5 shot, group at 30 yards indoors with my Taurus which is plenty good enough for me to shoot hogs with iron sights.