Had mixed but generally positive experience with BA flights to the States.

Most recently in MIA, with elderly mother. No need for assistance at LHR, as we plan adequate time for the process and know our way around.

The sheer distance at MIA, and the unpredicatblity of immigration led to the request for assistance.

The intial problem was that the waiting team denied all knowldege of our booking. This was despite confirmation at check in, boarding and on the plane that it was in the system.

We had to wait 20 minutes at the end of the jetty before the MIA specal services agreed that they had the wrong list of passenger names, and that they probably had been given the list for the previous or next BA flight.

After that bad start (including hints from them that we were trying to 'freeload'), the service was really good. Seamless and helpful progress through immigration. Not equipped to deal with baggage, but approached the fact that mother had 2 suitcases + a carry on (in addition to the ones I had) in a problem solving manner.

There was no question about the size of the tip that the allocated staff memeber was expecting - a large one. But I am accustomed to this in the USA, even if in the UK such a level of tip would not be expected or given.