Pros: Price, Portability, Quality
Cons: No low battery warning
I have had this amp for some time now and it's pretty great for the price I paid for it. Battery is pretty decent. I don't really use the Bass Boost feature much because I feel like it's too much... but it can also be the Bose OE/MIE2i that I have used with it. No real complains other than when the battery dies, it simply dies. No low battery warning, nothing at all. Can be charged using any USB port (wall chargers are faster).
for me it acts as an amplificated cord. it doesnt do anything to the sound it just helps elongate the life of your batterie......
i use it with an ipod mini, archos 605 and my nokia e75. the earphones are either ethymotic research hf5 or grado sr60.
these days maybe not ruining the sound with such money is an accomplishment by itself........
i think maybe it's wiser to buy an extra batterie ......