I got my SMC kit used. Its an old round bottle type. It's allowed me to run 20psi at 27 degrees timing on 91 pump, with zero knock retard. This is just with regular isopropyl alky and a little pump lube. I havent even tried to bump it up higher yet. I have to install my 340 fuel pump and fix a few things first. Given that its used, someone may have changed the wiring, but the wiring I have totally sucks IMO. They've used some cheap 4 or 5 core shielded wire thats not meant for a life in such a blazing hot environment. Its got melt marks all over it, and its not long enough to tuck it away cleanly. I also hate the bundle of wires that drape down underneath the controller. Its a real eyesore. One of these days I'll totally redo the wiring with some nice high flex (high strand number) wire, and try to make it look OEM. Another thing I dont like, is that with the way the nozzle connects to the up-pipe, it leaks no matter how tight it is. Its not a great design. I've tried to seal it up with all sorts of goop, but it never works. Every time I hit that button, I smell alky cause its being sprayed all over my engine. 
