Go with Charlotte. I did and have done very well. Prospects on the horizon are even better.
I'd avoid anything in Cali - really tough to evict tenants and it changes the whole dynamic as a property manager. I'd avoid the major cities in NE in general, older buildings and harsher weather leading to more R&M.
There are exceptions but from my experience it seems to me like code enforcement is a lot tougher in the NE and in the South code enforcement is either less stringent or more reasonable. The code enforcement agents in Charlotte have seemed very reasonable in every instance I've dealt with them.
I've scouted real estate in almost every major city in the US however I haven't been to KC. Part of the reason is there is nothing that made it stand out.
Charlotte is one of the fastest growing cities in the county, a day trip away from the beach or mountains, and has great weather, low crime, tourist attractions, and a great diversified economy. I think that it will keep growing for a while. NC laws are very landlord friendly as well. Great place to invest in real estate. That and the reasons above are why I moved here. Seriously consider Charlotte and if you do decide on Charlotte, private message me. The REI world is a small world even in a big city.