All these discussions in the end boil down to price, how much do we pay for it and what can it do.
Like General Bogdan so poetically said not too long ago, the risk is that we'll be paying for a Ferrari while getting a Chevrolet.
The F22 or Typhoon might well be also Ferrari or Porsche priced but they do deliver accordingly with plenty of room ,spare space, weight growth margins, engine margins, etc... to make them good for at least the following 40 years, I'm even less convinced today that the F35 has the same margins.
Raytheon had a good piece about the doubtful future of Stealth a couple of weeks ago, the best part of the F35, it's sensor suite, is perfectly usable by all kind of weapons platforms be it partially or as a whole ever since 2010 according to Northrop,
Even the Chinese are not betting on stealth for their next mainline fighter(s), the J20 will be a low volume fighter bomber, the J31 is deemed only good for export, they are going with 1200 J10's + all the Sukhoi ripoffs they are currently building.
The PAK-FA level of stealthiness is nowhere near that of any of the US
LO fighters, it is first and foremost a very high performance machine a la F22 and EF.
I just don't see how a 1 engined 60,000 or 70,000 lbs fighter is useful for nations like mine or as the main fighter for the US DoD, about 1/3-1/2 more fuel consumption ,also means 1/3-1/2 more tanker offload need.
It is too much machine for the bulk of the conflicts we fight or will fight in the future and it is the wrong weapon to fight it's sole credible adversary (the Chinese) if things ever come so far.
As an example, just look at the S-Koreans, please tell me why they need the F35, apart from numbers the N-Koreans have nothing that even remotely poses a threat to the S-Koreans and in the unlikely event the S-Koreans need to strike first (the nuclear danger), Long range SAM weapons , cruise missiles, Drones (think X47/Taranis-like) or brute full frontal attack are all more suitable than a limited force of F35's with a very limited weapon-load in case they want to stay stealthy.
It's bad for our finances
It's bad for our forces.
It's bad for our future defense industry.