On paying for twin seats - on my regular route I prefer to sit in one of the last three rows of the 777 (twin seats) as economy deplanes from the back door onto a bus. Since the introduction of paid seating for Gold members, I've learnt that there are always several pairs of twin seats available at check-in, on this South Asian route at least - few others want to pay, either - so I just change my seat to a twin an no cost during on-line checkin. Not sure that would work upstairs on a high-Y A380.
Similar experience, I virtually never sit in twins because they're all taken unless I book far in advance, but as I usually purchase tickets 1-4 weeks before departure most are already taken, usually travel alone so prefer the front mini-cabin on the 77W, but travelling with my mother last week on separate PNRs and her being on a Special ticket at exactly T-48 tried to get us seats together but EK had assigned everyone seats automatically (annoying!) but lo and behold.... 46A and B were available, best seats in the house when travelling together (first row of twins, with an entire seat's width of space beside the aisle seat). Only downside is pax queuing/stretching there but that's a very short part of the overall flight, was very pleasant, also that I could run back and grab another Tiger whenever I needed one (the crew put them in the ice drawer for me
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