Re:
Having ridden three different Cats Wiskas, including the one in the MBUK article above, I can say that they are all different from one another.
One is very fast and lively, one feels very similar to my 1992 DOGS BOLX and the third is a bit of both.
From this I conclude that if you wanted a meaningful comparison between the DOGS, Cats and DONKIS, then you would need three frames of near identical dimension and very similar weight, what you would then be comparing would be both the skill of the framebuilder and the characteristics of the tube, for instance Columbus MAX OR feels totally different from Reynolds 853, and both those frames were made by Dave Yates.
It would be great to get a bunch of these bikes together and to ride them all and compare notes, but I don't think it would prove much, other than each bike is different and what one rider likes another may not.
Shouldn't stop us trying though, so I'll volunteer a DB and a couple of Cats (the third is shortly off to a new home).
One proviso: You break it, you fix it!