I have thought about the .500, and have fired one. I would probably obtain the .460 magnum, built on the same frame.
The major reason I would want one is that they are extremely well made revolvers. They have to be to give the performance that they do.
Yes the .460, made on the same X frame should be a little more practical but still a little hot for me.
Of course I understand you could fire .454 Casull or .45 Colt in it also.
Like you, I would like to have one just to have such a fine revolver.