This has been on my board since it arrived, and it's not going anywhere soon.
I tend to run the pedal with the boost switch engaged, and the gain at about 10 o'clock. That gives a thick but clear overdrive, with a decent amount of touch sensitivity and clarity at the top end. It's great as a rhythm sound, and works well with both humbuckers and single coils. I love it for playing pop-punk stuff like Ash.
Rolling back the guitar volume, it doesn't clean up quite as well as some other pedals, but can still yield a slightly softer tone when that's called for.
Powering it at 12V gives a touch more body, which works well with my set-up.
Turning the gain knob higher yields a fuzzy tone which I think would work well for leads (it's a bit muddy for rhythm IMO) - but I have other pedals which I prefer for that usage.
It's got an absolute ton of output - even more so when powered at the higher voltage. I usually set the level knob at about 9 o'clock which is still above unity output!
The build quality is absolutely rock solid - this think is built like a tank. And the colour looks nice on my board :)