Plod,
First of all, you might want to address GR's point (based on the
data assembled by di Briganti - the link is quite safe): Most of the UK's initial 48 aircraft will need substantial upgrade work to reach what was once referred to as Block 4 standard. The cost of this work has not been defined. Separately, the USAF has made it clear that the central element of this upgrade, the new TR3 integrated core processor, will be required for future upgrades.
Second, the fact that a lot of aircraft have been built and that none of them have crashed doesn't mean the program has been successful. If you go back to 1996, when the first big contracts were signed, or 2001, when the EMD contract was issued, the declared objective (and the business plan) was to replace a wide range of US and partner fighters one-for-one with 3,000+ stealthy airplanes by the early 2020s, while holding procurement costs to F-16/18 levels and reducing operational costs. This target has been missed.
That's why the USAF is struggling with an aging fleet and the UK is trying to figure out whether it can (or wants to) afford more than the 48 aircraft needed (at a bare minimum) to equip the carriers. This would be a non-problem if the 2001 targets for cost and schedule had been met; and not too bad of a problem had the 2009 schedule been met.