Expensive, but top quality overdrive pedal which is exquisitely put together.
Sounds fabulous, from a subtle, warm bluesey amp-driven sound, to punchy full-on distortion; it's lovely (and looks good too).
I've used it with teles, strats, les pauls and gretsches and it brings out unique characteristics in each guitar beautifully. You can also use it as a great clean boost but the real beauty is in its sensitivity as a drive pedal. It means you can use your guitar volume control very subtly and the pedal reacts, it really does respond across the whole range of a volume pot's spectrum in a way cheaper pedals don't necessarily respond, and so it should bring out the subtlety of your playing if that's your thing. You can also whack it right up and go nuts if you'd rather.
I've only used it on fender blues jnr and deluxe amps (very clean) so can't say how it would work with something like a vox or marshall but my guess is it would be pretty good there too. The switch between high peak and low peak really gives you a lot of variety to play with.
I did a lot of research before I bought it because it is a lot of money for an overdrive pedal but if you're looking for top quality, the price is justified. In short: you get what you pay for - I was expecting quirky but it also delivers on quality big time.