After my AMS $10 birthday discount coupon, this pedal cost me a whopping $15. It's a very easy to use modeler of three types of very popular distortion. The Boss DS-1, MXR Distortion+, and the ProCo RAT. All great pedals in their own ways, and this modeler does its best to try and emulate them.
The following is my PERSONAL review on the sounds. Just my opinion.
The DS-1 model is unusable for me, but then again, I also hate the Boss DS-1. I've always found it to be thin and "tinny" sounding. Sterile, really. The Distortion+ and RAT models are both very cool. Do they sound like dead-on, faithful reproductions? No. But they are usable and fun to mess with. I mostly use the RAT model. It sounds a lot like the distortion from Nirvana's album In Utero... which I love.
There are two issues I have found with this pedal. 1- The gain sweep is minimal at best. From 0 to 9, there is very little variation in gain increase, then from 9 to 10 it is a HUGE increase. This doesn't bother me so much, because I always keep the gain dimed on this pedal. 2- When the pedal is turned off, you can still hear distortion. It is extremely faint, but enough to drive someone nuts, who is determined to have a pure clean tone, when the pedal is off.
Even with those two issues, this pedal is still an overall good buy in my opinion. Would I recommend it for live use? No. Between the sound issues and the plastic enclosure, I don't think it would be a good fit on stage/tour. Is it a fun, inexpensive pedal, great for home use? Yes. It was cheaper than a Fender footswitch and makes playing along to records that much more fun.
The function of Ds1 is the most accurate function with respect to the others, maybe with a little more noise. You can use settings that are on the internet designed for the original pedal without problems. The other two emulations do not serve, in my opinion.