I'm not sure I see much to recommend one side of the aircraft over the other really, maybe someone else knows better.

I would say that there don't appear to be many "better" seats (29c and 29h being the pick as you already identified), the exit rows are otherwise the only others that have a little extra to recommend them. The downside is possible queues for the loos, slightly narrower seats with solid armrests to accommodate the tray table, and the possibility of babies in the bassinet positions.

Keep checking for 29c/h availability, POUGs to WTP and finally asking for a paid upgrade at the airport would be my advice, keeping your existing assignment if all else fails. Don't plump for the middle seat - these *never* have anything to recommend them regardless of position.