First, nobody said it isn't a brilliant piece of technology.
But ,as the F version, it still needed a complete redesign for it to be anywhere near useful and even up until today it's got some big issues.
the lift fan also produces twice the vertical lift for the energy used.
So the 2700lb dead weight is easily outweighted by the 'free' 10,000lb of lift it produces.
So much for the law of conservation of energy.
Btw, the fact that it actually needs every single pound of that massive amount of vertical thrust is more a testimony of the overall state of the F35 and its obesity problems.
The death weight lift-fan isn't a small part of the vicious circle the F35 has seemed to spiral in to.
A common design -> space needed for the lift-fan +weight -> bulky design needed -> Extra weight to build a strong enough frame to compensate for all that extra weight -> Stronger thus heavier engine needed -> more fuel needed to achieve range , extra weight -> repeat circle.
they should have called the F35 the F35 Hippopotamus, it can be used on land and water, packs a good punch but is quickly out of breath, needs an enormous amount of food is rather bulky and weighs a ton (or 2 or3).
Structural issues remain to be a problem up until today and even with the most powerful engine available used in any of the fighters worldwide still doesn't make it anywhere near as nimble as the fighters it is supposed to replace.
PS I fully understand that the system used in the F32 (with the redesigned and much lighter tail) was also going to be a challenge for the VTOL version because of the lower amount of vertical thrust at hand but it still would've been a better solution even if it might not have gotten as much payload available as the F35, certainly not when solely used as a VTOL rather than the usually V/STOL it in reality really is.
More wing=lift and lighter Aircraft combined with the strong engine and the Ramp present at the UK CVG (and Italy, and Spain/Australia) would've made for one hell of a F32B, iso wanting the F35, the MARINE corps should have opted for fitting their LHA/D's with ramps (eg like the one used on the JUAN CARLOS which doesn't protrude too much into the available deck area ) and be done with it.
MARINES/NAVY carrier politics bit them both in the ass again it seems.
The way I see it is that the MARINES/UK needs where too much of a factor in the choice between the F32 or F35 ,this again combined with the knowledge that the F35 was Lockheed's last opportunity to remain a fighter constructor in the long run ,the F22 by then already was on the chopping block with 339 iso the original 750 with prospects on more reductions ahead.