subtle when used sparingly, abusive to amps when cranked
They are a great pedal but interact very differently with different amps, pickups and pedals.
I think you would quite like them as they work well with singlecoils.
I wouldn't lust after one though - you do pay for the paintwork, but then again if you buy one 2nd hand you won't loose out if you move it on as his stuff holds its price very well.
The youtube video by zach vex gives a good enough representation.
Dave has a clone version which seemed to have less background noise than mine