Is there a difference between Kansas City strip and New York strip?
The Kansas City Strip and the New York Strip refer to the same cut of meat. Apparently restaurants in New York City in the 1930's decided they couldn't sell a fancy steak named after Kansas City (where the stockyards and slaughterhouses were located). So, they just started calling it a New York Strip.
If you want a steak renamed by a egotistical chef, order the New York Strip. If you want a steak named for the cut of beef originally selected by butchers working next to the stockyards, order the Kansas City Strip.
New York Strip seems to definitely be the name that has taken off though, I'd never even heard the term "KC Strip" - and I grew up in Texas and currently live in Utah - far from the east coast.
I'd always assumed that though both were the same cut, the NY Strip included how that cut was prepared; i.e. with Garlic, Red Wine Vinegar, Worcestershire sauce and Italian seasoning (oregano, rosemary, thyme, basil, and sometimes marjoram). Is there any truth to that? (I guess it's slightly implied by your last paragraph's "chef vs. butcher" comment)