It depends how often you shoot and your energy level. I vote Stainless steel.
Can you imagine the hassle of blued cutlery?I had a carbon steel chef's knife, and although it held a much better edge, it was almost always a little rusty.
I have two original black powder pistols, and I have to clean the rust regularly, even in the off-season.
Yup, I think that deep blueing is beautiful, but I like modern stainless for functionality; sometimes I get home from the range....frigging tired and I want to eat something and then have a lay down for an hour or two.
My musket cleans fast and easy but my cartridge pistols? A little slower, and I need to pay more attention to detail.