Demo of the Lovepedal Amp Eleven GOLD.
http://www.lovepedal.com/
My take:
The Amp Eleven GOLD is a very tough, aggressive overdrive that I mostly use for sustained lead tones or higher-gain, big rock power chords. The GOLD version has independent switching between the boost and overdrive sides (so you can use either side OR both together). The boost knob is actually a bias control, turning it up adjusts the bias of the transistor inside the pedal. This has the effect of more and more saturation / compression / overdrive, and works interestingly well with the volume control on your guitar. The combination of the overdrive and boost sides is my default lead tone.
From the Lovepedal website:
"AMP ELEVEN™, fat, organic tone of an overdriven tube amp – with separate controls for bass and tone. Additional boost circuit. Kick the boost footswitch and you can instantly pivot from gritty rhythm riffs to screaming leads…or anything in between."