I was lucky enough to snag VCF # 7, a four knob version with external resonance control, from Donner's BJFE Customshop. These are my experiences thus far...
I really wanted a filter than would be more dynamic than others I've tried, with a usable range of sounds and without the worthless extremes often found .... well, BJ certainly delivered all that and more with the VCF! I could dial in the responsiveness and shape the effect exactly how I needed it between my Tele & Vox.
The controls are very interactive, providing a seemingly endless range of textures and whacked out effects. Everything from static filter sounds to wide sweeps that would be fat enough for Bootsy! Much like the two stomp mini vibe, I can't imagine the VCF without the external resonance control. It opens up some of the range of the other controls and by allowing you to tame these extrems it makes some of the crazy sounds more subtle and usable, for those times when you need that type of thing.
Best of all, the VCF seems to be a slow burning, rewarding type of effect. Not such instant gratification, like the MGMV was, but all about subtle changes of shade and sweet spots that will all become apparent as I spend more time playing and tweaking.
It also combines nicely with my recent habit of ditching a pick and using my fingers much more often. I found a pick seemed to "come between" me and the touch-sensitivity of the pedal and I got much more control and enjoyment from using my fingers.
My favourite use is to play unison bends or double stops into the VCF and sustain them until the decay folds in on itself and the filter gurgles with the two notes for a second before swallowing them whole! The VCF seems to do this in a more musical and responsive way than other examples of this effect I've tried. Hope to record some clips soon and will of course share them here.
Big Thanks to Donner & Bjorn!
Tea.