This is the only filter that allows you to process subsonic signals, aka modulations. Plug in a random or complex LFO form in there and shape it via the filter's different modes, and resonance !
I know this module has other great features, but this one alone makes it worth its buck for me. I know it's also a regular multimode filter for audio signals, but I haven't even tried that yet because I'm having too much fun creating new modulations forms. (so I put 5 stars for sound because Thomann wouldn't let me leave that blank, but honestly I have no idea how it sounds)
As usual there's their trademark maximalist engineer's approach of let's put every feature we can think of in this module. That includes bipolarly attenuated voltage modulation of every parameter, two signal inputs, three frequency modulation inputs, etc.