the Malström is one of the best synths i have ever heard. it is capable of producing anything from beautiful lush pads\strings to sub bass.
Subtractor is a great synth as well; it's best used to produce leads + bass. you can get anything from a square drum&bass bass, to a deep 808 bass drum. on the other hand, it can produce amazing leads etc'.
in any case, at the end of the road, both synths can be used in order to produce anything from mysterious pads and orchestral strings, to deep basses and penetrating leads.