I have a new hypothesis on those - last flight out I picked an otherwise empty row and ended up with an extra wide (not really POS, just very wide) guy next to me because that was the only E+ where a couple could sit together. So the my new thought is to go for aisles where the window is already taken, because nobody wants a middle but lots of people want two seats together, and the E+ seats are a nice target.

For tomorrow I just accepted the upgrade offer - I'd posted the details in the TOD thread already but this one makes more sense.

Premier Silver, LAX-IAD
after booking: $224 (the price difference between non-ref and changeable for a new ticket, plus $10)
At OLCI: $249
seconds later while reviewing the reservation: back to $224.

I have a bunch of work I need to do and it will be a lot easier in F, so I took it. It also gives me the extra pqm to bump me to silver for the year in case I manage to get out of my remaining trips this year.