i have one of their voltage adjusters and it has worked fine for years on my silver top. also have the hand held adjuster still. No problems with them that i have experienced. Just never used the ignition unit
I haven't, but I once read a very good thread where a guy used one on a carby 6cyl holden (I'll see if I can find it). You can set up separate spark maps depending on your situation (he was running petrol and LPG). For what it is (and the results I saw) I think its reasonable bang for your buck. Only downside is you have to set up your spark advance with the fiddly little hand controller.