DS 1 is not that great sounding to begin with. It doesn't sound horrible, and with the right amp it's got a nice generic distortion sound to it, but it's not exceptionally warm, doesn't have a lot of drive, and it's not a very smooth sounding distortion either.
The main differece between the older and the new DS 1s is the chips they used. Analogman does a mod to the old ones to make them sound better, and does a mod to the new ones to make them sound like the old ones. I've had the Keeley and the Analogman pedals both and neither one changed the sound of my Taiwan DS 1 that much. I liked the Analogman mod better, but eventually sold it and bought a germanium Fuzz Face that Analogman makes called a Sunface, way better pedal. I sold the Keeley and bought a Big Muff.
Instead of wasting more money on a pedal that isn't worth that much to begin with, save your money and buy something nicer, there are tons and tons and tons of distortion pedals out there that will sound way better than a DS 1. Check out proguitarshop.com for some demos of different distortion pedals.
