Thanks for bumping this thread, good stuff there by MR HUGHES, I forgot about this thread as weeks then months went by.
What I think attracts me to the Hammer scores is the style, often quite distinctly different from the 'Hollywood' sound (which I also enjoy) and also distinctly different from the style of other British films, such as the 40s & 50s war films with their Walton-esq Imperial flavour.
There is an edgyness, a modernism to many of the Hammer scores, avoiding the direct use of either the lush 'golden age' styles or the Elgar derived 'British Empire' music, but also avoiding the overt pop influences of the mid 60s onwards. Charting its own unique post-war style. I find that interesting and enjoyable as a counterpoint to the mainstream in film music.