I have flown in-direct to get to Orlando with my family and with work to Rochester nys, the only problems I have experianced is when the connection time is tight and the flight from the UK has left late, but having said that never missed the connection. As previously stated Charlotte airport is ok never found it too busy. If you are checked through on one ticket and using one airline all you have to do is drop your bags on the connecting flights belt.
Although flying direct is obviously better, my wife who is scared of flying has no problem with an indirect flight as you clear immigration and security and have a chance to have a walk and also a drink in a bar and then you arrive in Orlando classed as a domestic arrival so no double bag handling etc you are already chilled out.