hardware/software on the F-16 and F-18 etc. almost indefinitely and just make newer and better weaponry to go with it. I'm biased as I work for a missile company, but it seems to me that the missiles are more important than the platform once you have a minimum of stealth, speed, etc., especially in the wars we fight. I think the F-35 is meant to be a stealthy, fast, maneuverable, versatile (VTOL, etc.) aircraft that they can just upgrade pretty much indefinitely. It's not great at any one thing, maybe, but it can do it all and, like I said, the armament is probably more important than the platform once you have the bare minimum stealth, speed, maneuverability, etc. Don't know, though. It's not really my world (at least at the moment).