Pros: Best bang for the buck bass amp out there!
Cons: Constant buzzing heard when charging while listening, via USB. Thus it's better to let it charge overnight, and enjoy the Zo unplugged from the USB.
I can't even begin to say how well the Zo works; just as advertised, no ifs and buts! To keep things short and simple, if you want powerful, thumping, top-notch quality bass gain, you need not look anywhere else, ever, again! When it comes to amps, I'm a skeptic, to say the least. While many offer potential 'tweaks', which (to a lesser extent) can be acquired through careful EQ-ing, the tweaks are hardly ever worth the premium paid IMO. The Zo on the other hand is priced competitively, and is in turn the absolute best bang for the buck. Monsterous sub-bass gain, with no noticeable midrange bleed whatsoever; coupled with a warm presentation that pushes the entire signature slightly forward and in your face (else the bass would seem too overpowering, were it not for the treble and mids pushed slightly forward). Seriously, stop reading this, and pick one up. You'll never revert to listening without it again!