Don't forget that even on the supposedly new routes there are the occasional equipment changes. I booked a recent Asia trip around the SFO-HKG route to get the new configuration. On the outbound I got the new configuration but on the return I was informed at check-in that due to an equipment change it would be the old configuration. They offered to sell me a F seat when I asked if they could bump me up or let me upgrade my seat to F.

Then of course to add insult to injury, after boarding the captain announced that there would be a 3 hour delay while they changed one of the front windows in the cockpit which evidently was leaking. So we got to deplane and watch as the mechanics hung off the side of the big bird and changed the window. They even applied caulking when they were done. I did wonder how well that caulking would cure at FL 370 over the Pacific...but it seemed to hold up OK.