I've just read Hooker's Not Much of an Engineer, and for the first time have got some sense of what was good about Whittle. Hooker, who first got established for his work on the Merlin supercharger, was obviously surprised, and a bit miffed, at how good Whittle's centrifugal impeller design was, and that Hooker couldn't improve it. Hooker is a bit equivocal on centrifugal vs axial compressors (it's not helped by the fact that he obviously loathed Griffith), but he says that Whittle's design was so good it was the more practical choice in the short term.
As a schoolboy in England, I was brought up on the Whittle myth (Whittle undervalued? which UK was that in?): as so often with British aviation history, it was turned into a morality tale about how bad Government is at doing everything, and Whittle was praised as a visionary, thwarted by civil servants. But there's a fine line between being visionary and being impractical, so it's good to get a sense from Hooker's autobiography that there was a lot more to Whittle than Leonardo-type big ideas.