I think it gets unfairly derided sometimes (probably because it can generally be found for $30). By itself it's nothing to write home about but you are right - it sounds really good as a booster, IMO. I use it exclusively for that purpose. My DS-1 gets more board time than several higher priced distortion units. A+
Well, you know, there ain't a lot to it. If you want it to sound a little sexier, try replacing the diodes with LEDs. Or germanium transistors, maybe. Or one of each, if you want some groovy assymmetrical clipping
mines never failed me. sounds fairly generic, and not massively exciting, but it's got enough gain for anything i've ever wanted from it. i'm fairly sure for the price it won't be beaten. i always forget it cost me less than £40. sounds funny when the batteries start going though - like a baby DS-1 trying to be all macho and not really managing it
Andy.
edit - shit. thought you were talking about the DS-1, not the SD-1. that things nice too...