I haven't tried all too many overdrive pedals but with this one in my rig, I don't feel like I have to.
It has an amazingly sounding distortion with a clear treble and lush bass register. I use it with a Gibson SG and a Fender Strat, and this pedal brings out what I deem the best of both. It's capable of both bluesy low-drive tones, AC/DC gain or Metallica distortion.
The only drawback I can think of is that the voice-switch don't seem to do any real difference.
Honestly, for the price I think this is a no-brainer.