The Crack in the World score is decent music. The Phase IV music is about as ridiculous as the TV movie upon which it is based; ants rebelling against the world … ho hum.
Both scifi films are designed for the slightly higher intelligent film goer who's into science or engineering, albeit the second film is for the entomologist crowd (a very niche audience). The score for Crack in the World is full of adventure, excitement, danger and intrigue. The Phase 4 music is full of synthesizer homages to insects, and really is a waste of CD space.
All in all I would have just preferred the Crack in the World Score.