I have the older Korgasmatron, that is a great filter, very gritty but also very versatile because it tracks 1 V/octave and can be used as dual sine oscillator.
I had the dual Borg, which also sounds nice, but I did not like, that you always had to put in a cable if you wanted to use just one of the filters.
I did not use the Befaco filter, but I have several other modules from Befaco and they all have the punkrock approach, so I guess that Sallen-key filter will be cool too.