We traveled most recently to MCI a year ago and I enjoyed the experience, despite it being fairly cold in November. I had gotten in on an earlier flight and my SO was on a later flight. The thing I loved about MCI is that you can "meet" your arriving party at the "gate"--of course you're separated by a glass partition, it's nice to be able to see them arrive.
The bad is what's been mentioned above and that's the lacking facilities once through security. Plus, there's no freedom to roam the airport once in the holding area and the lounges are outside security.
The largest plus is the prices flying in/out of MCI. Always been cheap for me.