People coming toward me, people coming from behind me, wheels rolling over my feet...
CLT was definitely designed as a domestic airport, not a major hub of a legacy airline as one of US's international gateway. Literally everywhere but the central nexus is extremely crowded with people, and the situation is worsened by the poor design of the boarding gate, which a huge line of people awaiting to board their flights spill into the hallways. The distance that may take a few minute normally will take significantly more in this airport.
Also, good luck finding a seat!
To add fuel to the fire, the food here is also expensive even by airport standards: more than $10 for the cheapest entrees anywhere.
Bottom line is that avoid transferring in this airport. If you must, don't tempt fate and give yourself more than an hour.
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tl;dr version
1) Overcrowded airport
2) Overpriced food