I have to admit that although I love Mancini`s jazz and easy listeing music, I was never a fan of his dramatic scoring. Compared with Williams or Goldsmith it often doesn`t offer a lot of surprises. Nightwing for example is rather boring. IMO. But Lifeforce is absolutely gorgeous. Elegant and sweeping. Full of emotions. And that amazing Main Title ! Glad I recently bought the wonderful BSX double CD which not only sounds much better than the original Milan release and it has the complete score.
Mancini started out in a composers pool at Universal and had a hand in many sci-fi/horror pics of the 50s, up to and including 'The Creature From The Black Lagoon'. Many of these film's scores were gang-composed by a lot of very talented musicians. Lifeforce was a return to his roots in that respect, and he came through brilliantly.