I can think of a some disadvantages from my own experience flying in Florida several years ago.
1. Most rental aircraft seem not to have facilities for using headsets, with many pilots preferring to use a hand held mike. Very difficult to hear loudspeaker over the engine noise.
2. Air traffic speak much too quickly for us poor Brits and tend to rush you.
3. They use a lot of non-standard (for the rest of the world) terminology.
I cant think of any other disadvantages.
