Boo - a pleasure.
I questioned the guys on the style of aircraft and they claim that the route does not necessarily determine the exact aircraft used (in some cases it does e.g. Manchester-MCO does not even have a UC section, according to the chap I was speaking too). You definitely want the new style of 747-400.
UC on the higher deck is combined with PE (30-40 seats), the lower deck then has UC (with bar) combined with Economy. Bar doesn't run too smoothly as the guys running the bar cannot easily tell who is UC and who isn't given the spread of UC seats and the mix between UC and PE strolling down the stairs. So, on this split configuration, upstairs is fairly quiet but the service is mixed and the stewards are split between floors. Downstairs is a bit hectic with punters from all classes strolling up to the bar and ordering free drinks.
The seats were J2000 on the new plane and not on the older one. On the new plane, the system was video-on-demand - and it worked very well. You could even send text messages to others on the aircraft!
Enjoy!