It's called an overdrive but it's designed to replicate features one finds on amplifiers in a way that lets you configure how you want your amp to sound.
You can decide whether you want ghosting or not, whether you want negative feedback or not, whether your poweramp is silicon based or tube based, etc. It's complicated enough that you really have to read the manual, yet every option it has is available from knobs and switches (i.e., rather than in software settings).
@Tonray's Ghost It is a lot of knobs. So far I'd say despite the complexity and price it's worth it. Granted, the price I got it at is close to what they go for used.
@golem bought this bad boy over today for me to try it out. It was very impressive. I quickly dialed in tones which emulated other amps on overdrive settings (Mesa Recto, Marshall Plexi, Marshall JCM800, Friedman BE-OD, Fender BF). The 'tube rectifier' & 'solid-state rectifier' simulations were convincing, with the former having just enough sag (a lot of emulators overdo the sag). I also dialed in a couple of 'clean' tones, specifically a Vox and a 60's Fender Blackface. Both sounded convincing, although I was playing though the Blackface channel of my amp.
I really would like to know how they are emulating the ghost notes (speaker cone cry) without digital help. This is extremely subtle, but then again so is a good amp when it does this effect.
We were discussing that this pedal was not a runaway success and I think @Tonray's Ghost comment alludes to a misnomer, which is people think it is complex. There were only a couple of controls that I needed explanations on. I think what the controls do were thought out exceptionally well. I find that on many pedals, there are sweet spots on the settings and the as you approach one or both extreme settings (all left or all right on a knob, for instance) are not musical. On this, there did not seem to be an unusable setting or combination.
As I told Chandler, this would be an awesome 'foundation pedal' (amp emulator) for live for derivatives of say two amp sounds. This pedal would be a session player's dream.
And I think that is exactly the market...the session player or professional music creator. Not really worth it for live playing as you can achieve a great tone without that much fiddling beforehand with a few standard pedals and your amp or Pre-Amp pedal...but in a studio where some prima-donna personality is directing you to get just 'that' tone for his stale hits re-issue CD...is where it can shine.
Perhaps @Tonray's Ghost. I'm not a session player or professional anything related to music. This gets me some tones I thought I'd have to pay $2-3k to get. I'm in love.