Sometimes low tech is fine
"There's a real risk we do another Eurofighter - tarting up an old design with new bells and whistles. "
If only the Eurofighter was just a tarted-up old design. The French Rafale was based on existing technology and hence was relatively cheap and put into production in a few years. In contrast, Eurofighter is technologically very ambitious, and as a result, twenty years have passed since its prototype first flew (the "EAP": I forget what that was an acronym for). During this time, the enemy has changed, and technology has moved on anyway, and this multi-billion pound project has drained resources from more sensible procurement programmes. Being a four-nation procurement programme didn't help. Meanwhile, the RAF has lacked a credible fighter since at least the 1970s.
Pushing barriers in defence technology is very expensive and can just trigger an arms race with your enemy. We should only do so where there is a credible threat and a shortcoming in our capability. In the Eurofighter case, a bread-and-butter fighter would have met our needs.