Another thread mentioned some international connections even allow using transit facilities, long closed after September 11, and shorter queues in immigration. I'm hoping more folks will post verifying all this.
Originally Posted by number_6
MIA is much better now that the D terminal is open, there is an AC airside, and it is possible to connect airside between most gates (but not all). The MIA horror stories are mostly from a year or two ago when it was necessary to go landside and reclear security for many connections, and it could take hours (really!). A lot has improved at MIA in the past year.