But it should still be at a disadvantage compared to an F-35 that takes off conventionally with that engine, right? I mean, for the same engine performance, a conventional take off would always give more load or range, wouldn't it?
I'm not really sure of the wisdom of having an all 5th gen fleet. Most of the conflicts in which USAF is expected to participate, would not need expensive assets like F-35s to do the bulk of the work. For instance, dropping munitions on insurgents like the Taliban or Iraqi militias - why would you want to do that with an F-35? Wouldn't a good old F-16 bring a lot more value for money? If you take any recent war the USA has engaged in, how much of it was done in an environment where air combat or SAM threats existed?
And that is likely to be the case in most of USA's conflicts in future too. The USN's subs would send a barrage of Tomahawks at the enemy's air defence systems (like Libya), or the stealth aircrafts will do that in thee first few days. After that, shouldn't it be cheaper, non stealth aircrafts that do thee bulk of the remaining work?