Andrew; as far as I can recall, I think that
every report I've ever heard about the Wellbrook has been very favourable. Quite something for a unit which originally used two plastic transistors on a piece of veroboard, according the the Wellgood site. Of course, the Wellbrook team probably spent a lot of time getting to that point.
Regarding the clones, this site is interesting
http://valentfx.com/vanilla/discussi...ellbrook-clone
It's fairly long, so I printed it out in Word and edited and highlighted it anyone wants to see that.
B