We have flown through Charlotte, both ways, several times now and have never missed a connection yet. The layover going to Jamaica is typically 45 minutes to an hour and has always been plenty of time. That said this year was a bit different. Our flight out of STL was delayed about 35 minutes taking off, we arrived in Charlotte with less than 30 minutes till our connecting flight to MoBay was scheduled to take off. We "ran" through the airport, taking only time for short restroom visits and made the gate as it was boarding. We were the last ones to board, but we made it.
Coming home was another story. We left MoBay on time and arrived in Charlotte with our usual 90 minutes or so to get through immigration/customs/security and board our connecting flight back to STL. Immigration has a new wrinkle, computer kiosks to check your passports before going through a human to check your customs forms and let you through to the baggage pick-up. There were some two or three flights that arrived at the same time so there were about 600 plus hitting the immigration hall at the same time, we were lucky to be near the head of the line. As it turned out our flight back to STL was delayed about an hour so we would have had time to eat a bit anyway, if we wanted.
Anyway, an hour going down and an hour and a half coming back should be enough time on most occasions. It's all just part of the adventure of travel in these days of security checks and such.
I have a question: Anyone familiar with the new "Pre-Check" status for some travelers? My wife was designated as "pre-check" and I was not. It seems you can apply for "pre-check" status through the TSA web site. It allows you to go through an expedited security line at participating airports. You don't have to empty your pockets, take off your shoes or belts, or remove your laptops and 1 qt. liquids baggy from your carry on. It does speed things up considerably.