I took the hound on a more involved mtb ride... I only pushed it once (just after the 20K mark), 12% climb on wet grass with rubbish tyres that would not grip... other than that, it was good fun and actually took some rocky downhill with a lot less care than I would with the big bike. The mini velo is some small, it can go faster through some technical twisty bits. Only time I was smaller was on the big rock as I was just about clearing the bottom bracket.
I ' m going to fit either Conti explorer or Schwalbe Black Jack to see how the minivelo gets on even rougher trails.
With Disc brakes, it would be really good and Mud clogging would not matter; this is the current limitation.