I'm on a team sometimes on the Memphis circuit. Its a little between serious and party for the team I'm one but I'm just in it for the fun. It can be expensive and sponsors, if you can get them, really helps, but in some cases that just makes for more work. You can choose to do the smaller ones, the big ones, or both. Just depends on how much time, money, and energy you want to put into it.
I work with 2 girls that cook at some of the smaller competitions around here, and they've been very successful. They prefer the ones that use Kansas City rules.