His writing for a pianoless seven-piece ensemble had economy, daring and just enough whimsy to prevent the music from perishing of an overdose of self-regard, the fate of so much avant garde jazz of the sixties.

To read the whole thing, go here. Later, there was another Rifftides piece about a Collier reissue:

The looseness and cogency in Collier's arrangements are in ideal balance to contain the wildness, daring and--it must be emphasized--good humor of the soloists. There is no trace of the anger and willfull distortion that marred so much avant garde playing in the final decades of the twentieth century.