I'm glad you solved your problem, but for the benefit of others who may be viewing this thread, we have done both. And Charlotte is the better way to be routed if you can. Miami is a nightmare of an airport. There will still be long lines at customs, etc. in CLT, but since it's a smaller airport it's easier to get to your connecting gate. We avoid Miami like the plague; in the good old days when we could connect through San Juan, that was the best. Charlotte comes in second.