It's a more dynamic Fulldrive 2 AND it has a separate boost channel. I used to play with a Fulldrive 2 but the boost was hardly relevant (perhaps for lead soloing). Now the boost gets more playtime than the drive channel because it just works. In terms of hardware it's exactly a Fulltone 2B pedal, with a drive channel that surpasses the Fulldrive 2 (yes I'm convinced of it). Funfact: I got serial #21 for my 21th birthday, say what!?