To be honest over the past couple of years I have tried to avoid the US (as well as LHR!). Recently I had to do a trip to FLL and Brazil and I had no choice. I was pleasantly surprised that contrary to my last visit everyone I came into contact with was friendly and professional. Even in MIA where I had been told it was a zoo, I found the TSA screeners to be efficient and courteous. Maybe I was a lucky, but that is irrelevant. I feel a lot happier about transiting and visiting the US than I did a year ago.