The old 747 that sometimes get subsituted on long haul to CDG offer the previous generation of long haul F seat. The seat is covered in violet velvet and does lie flat. While not as exciting as the new F, it is a perfectly decent product where you can sleep.
Compare that to the poor guys in C, who have to contend with a craddle like seat for 12 hours... It happened to me in C on one occasion, coming back from CDG and I was NOT happy.