Charlotte airport parking daily lot is getting worse every time I fly each week. It takes forever for a shuttle and by the time one comes not everyone can get on the bus. The only advantage is you get to park your car in a garage.
Ignore any review older than 6 months. I've been using Charlotte International Airport parking since 2006 and have seen its ups and downs. If you have time, I'd recommend getting a lift to the airport or going to a parking lot outside of the airport (ie: Park n Go).