I have a dsr1. It hasn't given me any troubles. Took a lot of head scratching and fiddling to get it sounding right, but I'm happy with it now. I'm running a JL xd800/8 2 channels to tweeters in dash, 4 channels bridged to 2 for the front doors and 2 channels to the rear doors. Then an xd600/1 to a JL Audio dual 10" stealthbox. Keep in mind the dsp is only 8 channels so if you want to run more than that you're better off going with a dedicated dsp with more channels and the pac unit to sum signal to it, but for the money it's a good unit. Don't ask me how to set it up. It was 3 years ago and the how didn't sink in. With the maestro cable you get everything you need from the factory amp under the dash next to the steering column, which will be disabled. It uses the digital signal from the head unit vs line level from speaker outputs to my understanding. One of the more important things is if the tweeters are on their own channels set the crossover frequency before you turn on the amp or you'll easily fry them if you run them prior to adjustment. Don't have to get them tuned. Just set the frequency high enough to stay in the tweeter range. I bought mine locally so the guys at the shop were helpfull with the tech support. Without that I'd have been screwed.