My last trip through MCI was over New Years 2002, but it's kind of like the 70s gates at SFO before 9/11 - the security screening station is at each gate. So instead of being funnelled into a single security station, the lines are usually much more reasonable since only the people going to that gate are in the line.

United's ticket counters are across from the gates and they did have a general Premiere-level checkin line. Only about 2-3 stations, however, but if you're on the last flights out to ORD and DEN, it's probably pretty lite.