Mr. Sprey is a respected expert in his field but nearly most of what he's states in the video has been debunked by former colleagues and F-35 test performance goals. That being said and being a follower of the program, yes, there have been a lot of teething issues but there are two main aspects to consider here regarding the cost overruns and delays. One, since WE (the USA) are the designer, I will honestly put it out there that it is our procurement and political system structure that causes these defense cost overruns. It is a matter of how many elected Congress members can get their "fingers in the pie" for spending in their districts or in a colleagues district. That plus all of the different procurement regulations and laws make our costs disproportionately higher than they should be. Second, the original promise of the F-35 being cheaper than the F-22 was not off the mark, but the threat environment has drastically changed since the original JSF plan was issued and thus the mission requirements and aircraft component requirements have changed with it. What most folks do not know(and there is a LOT of disinformation/misinformation out there on the F-35) is that the original plan was for the aircraft to not be available until at least 2015 or later due to the need for it's technologies to mature and this being contingent on there being no major issues. So the program is not actually behind schedule, but due to the formerly mentioned point(design changes), it is over original budget. The other issue is that the decision was made to try and move the F-35's service entry date up by several years and since the core technologies were simply not ready yet, that decision was hasty at best and certainly added headaches for the engineers. So, things are catching up and the issues that remain on Lockheed Martin's end are mostly minor and the updated policy on the F-35 procurement is that if one of the aircraft on the assembly line has issues/flaws or is delayed, the cost for that comes off of Lockheed Martin profit per aircraft (which is completely fair in dealing with overruns). The one issue I have is the engine. Our Congress killed the Alternate Engine by General Electric which at first, seemed like a good idea but in retrospect, the PW F135 engine is now the single biggest issue with the F-35 design. PW makes good engines and I am sure they will fix the issues but when it comes to Defense, it is always a good idea to have major component backups just in case.
So, the question remains, what will your Air Forces be getting with the F-35? Stealth, yes and other core technologies that no other aircraft have which will help it mitigate both air to air and surface to air threats which at current capability level, all non-stealth aircraft are technically obsolete within the latest and forecast threat realm. One of the other key core components is the DAS system which will give the F-35 Pilot full 360 degree omnispherical passive threat detection & identification and the ability to engage those threats at any angle. For example, with the current and next two phases of the AIM-9X missile, the F-35 Pilot will be able to see an air to air threat, identify it, fire an AIM-9X and Lock After Launch. This capability is Over-the Shoulder and the final phase AIM-9X will have a range of over 50 nautical miles. The F-35's current and soon to be added air to ground ordy will also have the ability to fire on distant or close targets at any angle. The above mentioned is only a fraction of the capability this aircraft will bring and there is no other aircraft currently made that is even close to the F-35's capability.
One other point, some have made issue that the F-35 isn't as maneuverable as other current fighters. Not so, it's extreme AoA performance is better than any non-thrust vectoring fighter and it's instantaneous and sustained turn rate are at or slightly better than any other non-thrust vectoring fighter but in reality, if the F-35 Pilot uses the core capability, there will be no traditional dogfight, the enemy will be dead well before a merge which with current and forecast threats, any dogfight type close in merge is literally an unaffordable option. The other point about the AIM-9X being central to the F-35 is that there is serious concern over the possibility that there are significant electronic countermeasures that already exist that can jam radar guided missiles or disrupt their mid course guidance. That is why the long range/burn 2 to 3 stage motor for the AIM-9X is being developed as it has advanced IR guidance with mid course steering to-target before the seeker makes it's terminal lock on. The latest IR seekers are extremely resistant to flare countermeasures as they take a "snap shot" of the enemy aircraft's IR/Electromagnetic outline(it's skin friction and internal engine IR signature) and stay locked on to that image ignoring flares. There's reasonable belief that current and upcoming IR seekers are also immune to laser blinding from short range defense lasers. Also, the AIM-9X's thrust vectoring will easily outmaneuver the most maneuverable thrust vectoring aircraft in existence today.
Lastly, in time the F-35 will overcome it's teething issues and prove it's detractors wrong. Most of the current defense hardware now seen in the US and NATO has been through rough spots of development and thus have endured plenty of criticisms regarding costs and issues and along the way as well as plenty of calls came for many of those programs to be cancelled. I am confident the F-35 will prevail and perform well for a long time but bear in mind, these weapons will never become cheaper, only more expensive as new threats arise. That has always been the case.