Orca, other contributors,
I hesitated to post this, but I thought it would help put the F-35B and its performance in context. Please feel free to disagree and criticise anything - that's how we all learn stuff.
All aircraft designs are 'compromised' in one way or another. No one aircraft can do everything that any aircraft could do. The Lancaster was a superb bomber, but probably not a good fighter. The Typhoon is an awesome air combat aircraft, but not much good at hauling cargo. All aircraft are designed to meet requirements: some don't drive the basic airframe design (example - digits of cockpit displays must be at least 3.4 mm high, or something). But some DO drive the whole design (example - 'combat range of 1000 miles at low level at high speed' drove the TSR2 design).
So what drove the F-35 design? The requirements were driven by years of studies that showed a need to balance out and out airframe performance against required strike mission loads while exploiting low observability and more advanced sensor and communications capabilities. Internal weapons bays would be required to support a reduced signature. LO ruled out external fuel tanks as a solution to achieving desired ranges. All that would place pressure on aircraft internal volume, and that in turn meant that F-35 would never be a 'lean and mean' 9g dogfighter. The Key Performance Parameters (KPPs - JSF speak for key requirements) were carefully chosen to reflect those basic objectives.
The F-35B design was also driven by two key requirements that were particular to STOVL. These were to perform a STO for a given mission in a certain length - this figure was driven by the size of USN LHD flight decks. The second requirement was the vertical landing bring back (VLBB), calling for the aircraft to be able to land vertically with a specified internal weapon load. These two requirements absolutely drove the design of the F-35B. They could only be met by a powered lift aircraft that had enough powered lift capability and internal weapons bay volume. ( The F-35B team also had to meet a number of 'joint' KPPs, but the only performance related 'joint' KPP was that for mission radius. )
The choice of these two KPPs was deliberate and informed. The people drawing them up back in the 90s had realised that any powered lift aircraft design would experience huge pressure on internal volume (lift fans take up space). As a result, they only asked for the STOVL aircraft to bring back (or carry) 1,000lb class weapons, to give the design team some margin on both volume and wight. Unfortunately, in the early days of the development programme, the LM JSF team had a poor handle on airframe weight and internal design. Really poor. That led them to believe that they could produce a 'common weapons bay' design for all 3 variants, giving the STOVL variant the ability to carry 2,000lb weapons internally. They couldn't. LM then had to redesign the STOVL aircraft more or less completely, with the big change being reducing the size of the weapons bays back to the 1,000lb weapon size originally envisaged. (By the way, at that time, all three variants were grotesquely overweight and unable to meet any performance related KPPs - the B variant led the subsequent redesign effort, but all three aircraft were extensively changed).
The F-35B is not 'significantly compromised'. Its design is deliberate and aimed at meeting KPPs that supported operation from ships. It's damn near the size of an F-4. It can launch from a ship at higher weights than the F-4 could from UK ships. It can land on with 3,200lbs of internal weapons. Its sensor and comms capabilities are way ahead of anything else out there. And it can operate from ships that have got around 600 feet of deck. It's the future of maritime air power for those countries that can't afford, or don't know how to build, CVN type carriers and the aircraft to go on them. (Right now, only the US can do that).
My view (and that's all it is) is that the next few years will see more and more countries putting F-35Bs on a variety of ships, some called 'aircraft carriers'. The Japanese, South Koreans and Italians are al moving that way. The UK seems to be planning a joint UK/USMC air wing for the QE's 2021 deployment, with somewhere about 24 aircraft embarked.
Final point. I'm not an LM shill. I'm not an F-35 fanboy. I'm just an old naval aircraft engineer who has a little understanding of just how damn hard it is to design, make, test and deploy a supersonic STOVL strike aircraft to sea. I admit to getting a bit miffed when the efforts of extremely fine and clever people (not including me, by the way) are disparaged, especially when lots of those clever people are excellent Brits.
Best regards as ever to all those who are working hard right now to give the UK an outstanding maritime strike capability, and to those who are getting ready to deploy it.
Engines