I am unfortunately always in the position where the flight is full, but not overbooked. One would think a mid July flight to CDG would be overbooked, but it was 90% full in all classes.
I did however enjoy 81A with an empty B seat, so an op-up wouldn't have changed much in terms of space and accessibility. On a slightly different note, the crew were great as always, the SFS came and chatted with me for a bit (I even told her about FT and gave her a link to the forum) and then later introduced me to the Purser.
So just to shock myself back to what Economy class is really like, I'm getting on some Ryanair flights next week (and an AF one, we'll see how that goes).