It's good enough for small PCBs and other odd jobs. There are even CNC mods for it.
The DIY KIT contains a schematic. It's a bit low quality as small colored text was rastered on the BW laser printout. I could scan it when I get back home. Its pretty simple and straight forward. The only "nifty" stuff is the negative voltage creation for the opamps (at least from my point of view).