Typical major carrier hub. Overcrowded, bustling, hectic. Charlotte used to be a quaint airport but it has grown into a behemoth. Certainly not on the scale of Atlanta or LGA or O'Hare but on a smaller scale.
Like its bigger sister in Atlanta, don't try to connect here in under 20 minutes if you have to change concourses. Even within the same concourse can be a test simply because of the passenger traffic in the aisles and poorly designed gate layout where folks queueing for a particular gate block the aisle quite completely.
I did find it clean though. Restaurant selection was "ok" but breakfast places are lacking (Bojangles to the rescue!!)
Overall not a terrible airport.