I've got one in .457 WW, and agree with all others that basically you are pole vaulting over mouse turds.
lots of guys want something different so I guess this might fill the bill for them. I'm more into practicality, I bought this rifle used for $900 bucks, but I really wanted it as it's parkerized and I've always loved that finish.
I mainly use 45/70 rounds in it, but did buy a couple of boxes of the .457 as you can see it groups better with the .457, but not enough for me to keep buying the stuff, handloading you can duplicate pretty much what you see here.