It is interesting to note that British service personnel are also treated with a deal of respect when visiting the US. From personal experience even the immigration staff at airports are generally more amenable once you are identified as military.
Back in the UK on the odd occasion that I visit Tescos etc in uniform on the way home from work I often feel that I am being looked at as though I am a piece of dirt.
In the US I have never seen a gang of teenagers abuse a serviceman as he walks down the street. In the UK its a very different story.
I recently had an altercation with a bus driver whilst driving home from work. When I got out of the car and the bus driver saw my uniform his immediate response was 'Ah you're a typical RAF w****r'. It just led me to wonder where that perception of RAF people had come from.