“In terms of instantaneous and sustained turn rates and just about every other performance metric, the F-35 variants match or considerably exceed the capabilities of every fourth-generation fighter,” Flynn said.
I must say I would hesitate to suggest there is any inaccuracy in this statement as I believe the words were very carefully chosen (as one would expect!)
Firstly instantaneous turn rate is a no brainer. It is determined mainly by the AoA you can snatch without loss of attitude control. Given the alpha they have been to with the F35 I would not doubt the snatch capability is considerably more than many earlier aircraft.
Sustained turn rate is of course quite another matter. This is dependent on the thrust used and the induced drag present at the conditions where it is measured. Since we don’t know those details it is quite possible that there are circumstances where they are in favour of the F35 (and others where they are not!)
The “just about every other performance metric” clearly copes with the acceleration side of life.