They have an excellent website, including a forum section that will give you more info than you can probably absorb: http://www.msdignition.com/forum/forumdisplay.php?f=5

I've had a couple, they work fine. In high performance demand (basically racing) they get the job done. MPO is they are pretty much overkill for a street putter, probably half of them out there are for the boy racer look and never get pressed for their full capability. One of the ones I had failed once and I sent it back for repair. The service dept was quick and reasonable. For a street driven rod I prefer a self contained, ready to run electronic ignition, functions well, and you don't have to find a spot for that big clunky red box.