I actually actively avoid row 9: 9A has the protruding door, and it protrudes a lot. 9B is said to have a pretty thin seat cushion, and all row 9 has the tray table in the arm rest, which I found quite significant.
For a long flight, all this is pretty uncomfortable.
I am a lot on the 747, and suggest you go for the D/E-seats in the EC minicabin, as especially the E seat gives a lot of sideways legroom. (this is if you do not want a window or a wall to lean on).