It never ceases to amaze me how negative some people seem to be about the F-35B.
The debate over whether or not the -B should be scrapped 'to save money' is over. The money's been spent, the aircraft has been designed and built, thousands of hours have been spent in simulators getting the control laws sorted. The amount of money you'd save now by deciding not to flight test it is piddling compared to what's gone before. If you wanted to stop it you should have been jumping up and down 5 years ago. Now it's going to do huge amounts of risk reduction for the other 2 variants so if you scrap it you'll introduce delays to their test programmes of the order of several years - you'll be almost halving the number of instrumented test airplanes for pity's sake.
The variant debate for the UK is over too. I can't profess the ability or the inclination to explain the intimate detail of why the choice came out at the -B, but this wasn't the work of a lone barking mad loony. Lots of incredibly smart people will have done analysis of almost unimaginable depth into the UK's requirement. Dozens and dozens of Operational Analysts et al (boffins, geeks, historian-types, political whizz-kids, and aircrew) will have spent hours constructing worst case pictures of the possible threat scenarios that the UK could get involved in over the next 30 years. Even more procurement folks will have constructed huge databases of information about through-life costs etc. What I'm trying to say is that it's not a simple question of 'I like tail hooks, and if I'm playing Top Trumps variant x has a bigger range than variant y'.
As for LO and supersonic speed not being particularly important for CAS in a permissive environment - well I'd agree. But this airplane is to fulfill the UK's JCA requirement and there are a number of scenarios where stealth and speed can come in handy. When you don't need them, by all means bolt on the external pylons and twin-store racks and you have a very respectable loadout. If you need to go LO, then you can. And if someone comes up with an F-35 stealth countermeasure with a new system, that doesn't immediately render stealth obsolete. By that argument the fact that some IR missiles don't get decoyed by flares means there's no point having flares any more. An F-35 in the hands of smart operators gives far more options for developing counter-countermeasures than a 4th gen aircraft.
And finally - it's a whole lot more than just LO & a STOVL motor. The sensor suite alone is a reason to buy the airplane, as is the cockpit and the interoperability with um, just about all our major allies (can everybody be wrong - or is there a conspiracy theory to justify why it keeps getting selected?). And last but not least UK industry is doing very well out of the deal too.
Regards,
Single Seat, Single Engine, The Only Way To Fly