Tension Labs EAP03 has a lot of potential, but in the current incarnation it is not quite ready to be able to compete with the lesser equipped earphone amps which focus solely on sound quality. It does, however, have a lot of really unique features you will not find in another product on the market today, but even that is overshadowed by its relatively poor price / performance ratio sound quality wise. The features that left the biggest impression on me were the volume indicator and the integrated microphone. The microphone is a very welcome addition because it makes it hassle free to just tune away from your music and hear what is going on around without having to take out your earphones. In my opinion this makes the biggest difference when you use custom earphones because they can be tricky to remove and insert.
The sound quality is somewhat of a letdown because it does not boost the experience by as much as other amps do. If you value features higher than squeezing the last drop of performance out of your earphones then the EAP03 is definitely worthy of your consideration. All depending on what you are looking for. The Tension Labs EAP03 does a lot of things the right way, but I feel it fails to deliver a decent increase in sound quality.