I have a 7.5" Super Redhawk and I love it. I'd have to double check the loads but I run H110 under a 400gr Speer FP and Ramshot Enforcer with the 275gr Barnes XPB.
I run iron sights on mine and I have it zeroed at 75 yards. Both loads are capable of making easy hits on my 10" gong at 75 yards off of shooting sticks with 100% hits. It's more accurate than any other production revolver I've played with.
When I got the 480 I had planned on sending it off to get converted to 457 Linebaugh. I'm glad I didn't now. The 475 is awesome, but I don't think it would do anything that the 480 can't at reasonable handgun ranges. In fact muy 480 is coming with me on a January cow elk hunt in Utah. The goal is to use either the iron sighted 480 or my 338/375 Ruger Striker.