I agree with the other poster, if you liked StL you will like KC.
As far as doing things around the city, it can be arguable depending on what one values. StL loses Cardinal games (which would be a tough do anyway) as a benefit due to the timing, but many attendees probably wouldn't have the ability to attend them anyway. City Museum is great, but more for kids, and a lot of things in and around the city are "better" for kids. As far as things close to the arena or DT for that matter, StL doesn't have much.
DT KC has 8-10 breweries and distilleries that are within walking range of the arena, with another 4-6 that are accessible by scooters or <5 uber/lyft rides. There are a lot more food options between DT, Crossroads, and River Market compared to StL as well. DT KC is >>>> DT StL. You should have a blast.