I actually found it disappointing. It was mostly the author's impressions of Blake's physical appearence. Not much actual Blake. Worth the three minutes it takes to read, though.
He seems quite tactful. This is about Roald Dahl:
"I think he did know how to be - oh, what's the word? - curmudgeonly, you know," says Blake. "But my feeling about it was that he was often in pain or discomfort, and he would rather be a bit bad-tempered than actually complain - which is a thing I'm sure he'd never do.