Always find it interesting that, despite sharing many extremely distinctive soloists, the music of Collier, Westbrook et al always sounds individually unique - a mark of their compositional skills. Collier seems to lean more towards 60s mainstream modality than the others (not a criticism) - Westbrook's theatre/folk/contemporary classical influences go somewhere very different whilst after the first couple of albums Tippett goes much further out on a limb. The 'rock' influence doesn't seem as strong in Collier as in early Westbrook/Tippett and much Gibbs and Ardley. Possibly a bit closer to Garrick though Collier always sounds more searching to my ears.