Hi Mark,
With my long legs it can be a problem, some operators plan the seats with more room, I believe. I have done the Australia return trip seven times now, all on 747.
Regarding that incident, when we got back to our seats, I told the others about what happened, I think a few anxious people overheard me :-D. On the return trip, my workmate, who flies microlights, was commenting on how much the wing deflects after taking off and the woman next to me was about to have a fit, I had to tell him to shut up :rofl: