Well, it drops the volume slightly from your clean, but it sounds great if you run the octave mode into the Big Muff. It is also pretty good for recording. It is so cheap, I'd say yeah.
The dano trem is also pretty cool too. I had one and traded it for the french toast, still slight volume drop- but that is just because of the way tremolo works. For that very reason I want one of these:
it is a bit expensive, but it has a built in boost to get rid of the volume drop, it's sine wave is voiced to sound like a Fender vibrolux, and the square is voiced to sound like a Vox repeater (plug in effect that Spaceman 3 used to use.)
I'm probably not gonna have one for a long time. My current aspirations are a polyphase and a DD-20, as well as korg dt-10. I think then I'll be off pedals for awhile because I want to work on getting a car and getting a jazzmaster and maybe an epi casino (my friend has one that he never plays, I might make him an offer on it, I figure he'll sell it to me cheap because he got it cheap.)
BTW, there are a bunch of cool bends for your DS-1. We did bend A to my friends that seems to make the distortion a bit better, and also makes it oscillate at the highest gain settings. With a dano fuzz or distortion like his grilled cheese (which we destroyed looking for bends) or my french toast on before it (which generates does something cool to the signal) and then a chorus after it (might work with tremolo infront of it) we got cool police siren noises.