Thanks for the feedback. Sounds like the only real difference is that stainless, not surprisingly, is easier to clean and maintain. I wondered about this because Sig recently began making the legendary p210 in stainless and I wasn't sure why. To me the original in Nitron coated carbon steel just somehow seemed cooler and more authentic. Once it's produced in stainless, it's just another (albeit excellent) pistol.
They started doing the slides out of stainless. The frame is still carbon steel. I have an older Legend Target that's all carbon, thankfully.