I built the Synthrotek Dirt and Echo kits a few months ago. I love em both. The echo is used in almost ever patch I make.
I got the DS-M kit in and quickly built it up. Had some trouble tuning it at first. I used my Minibrute set to arpeggiator hold in 4 octaves with middle C. I had it looping while tuning until the tuning was near perfect. Tracks really well now.
The DS-M obviously makes great percussion sounds, but it sounds really cool as a VCO too.