I have never had an Op-Up to F and am never expecting one. I am flying LHR-EWR and JFK-LHR in a few weeks but am in a party of 3, 1 Gold and 2 Silvers. It could happen but IMHO, it is very very unlikely. The outbound is very quiet, the JFK-LHR flight may give us a little bit of a better chance as it is pretty busy but still, it won't happen. I am eager to try out 64K too, only been on the UD about 4 years ago and can't really remember it!