If I could just add my 1/2 penny worth - and possibly muddy the waters
Just flown a VC-10 EGLL-EGAA with no problems whatsoever. It was my fourth attempt though.
I had DaveB's problems with refuelling on the first two (6.6b) but found that I could not get rid of the full tanks when trying the 'Compare' method the second time around. As I was going to EGAA I 'binned' the flight as there was no way I was not going to run out of runway at Aldergrove with virtually full fuel and a full load of Pax (a Vat of 165!).
My first attempt at 6.8b was uneventful. That was until I turned off the runway at EGAA, stopped, called 'Ground' before applying the parking brake. Then...nothing happened...no 'bing-bong'..or anything!
Needless to say, when I quit FS I found myself still at EGLL but bereft of most of the fuel I had put in. It may well have been something I did - or did not do.
This last time I taxied to parking on arrival - no problems.
Tim