I bought this module to add a bit of stereo movement to my modular synth - but it does much more than that!
One of the more common uses I have for this module is to send the signal to two different effects chains / filters, so that I can add extra reverb so certain passages, or delay only specific notes,or adjust the timbre of the sound in interesting ways.
With two sound sources input it can also be used as a voltage controlled cross-fader, very useful for creating sounds that morph over time, or expressively with added pressure to a ribbon controller for example.
It can also be used as a spare VCA if you run out!
As always with Doepfer, the build quality is spot on, the features are well considered, and it is really easy to use.