There was an excerpt of Harriott's voice from a radio interview broadcast on last week's 'Jazz Britannia' and he came across as an intelligent, cultured and clearly spoken guy. He obviously didn't have doubts as to his own importance on the UK scene (rightly so IMO) and I suspect that by the late 60s a great deal of disillusion had set in. To his very great credit he kept on touring the UK and putting his all into some very low-key gigs, whilst obviously very unwell with the bronchial problems. His chaotic home life and lack of a solid base were clearly major issues though and by the end he was very much a drifter, relying on generosity of friends.
The Harriott biography is an essential read IMO. There's a great section where Charles Mingus breaks off his UK tour to visit Harriott in hospital in Southampton. Mingus wasn't allowed to visit at the early time he got there (just before boarding ship) so he left a nice message for Joe. Harriott in a Mingus group would have been well worth hearing.
That bit of TV footage of Harriott on 'Jazz Britannia' with Stan Tracey's Big Brass last week spoke volumes. Joe plays superbly on his Ellington feature, giving 110% but his face is visibly drawn (by 1968/9) and the health problems seem to have clearly kicked in.