My observation in flying BA and QF is that BA has 3 different versions of their F seat in service, while QF has 2 versions. The newest generation of seat is more comfortable, but neither is as comfortable as the CX seat (yet all 3 are the same design from the same manufacturer, just tweaked to the individual specifications). Thus your seat comfort varies from aircraft to aircraft and it is a surprisingly wide range. BA is upgrading their F seats much faster than QF (presumably the delay at QF was due to their decisions on enhancing service, sadly it looks like QF has not chosen to spend the money to get the CX type of seat even though it is a plug replacement for the current one.