The F-35B is only rated for 7G maneuvers, while F-35A is rated for 9G (F-35C 7.5G).
This is because the need to hold down airframe weight to preserve vertical landing characteristics produces a lighter but weaker airframe.
Other than the max G-rating, maneuverability is virtually identical between -A & -B... but again there is the lack of an internal gun for -B.
Cost is still a major difference... the more costly materials used in the airframe to bring down weight, added to the costs of the lift fan & its gearbox as well as the airflow doors, would keep that cost differential no matter what the production numbers.
Last edited by GreenKnight121; 11th Sep 2012 at 03:25.