First and foremost, let me say that Gary (the owner of Electric-Avenues) is seriously the friendliest, most helpful guy I have spoken to in a long while.  He was so helpful throughout the question/ordering process.  He made sure to answer every question I had very quickly, and even preset the gain on this amp for my Grado SR-80s (great pairing, btw).  As for the sound quality, I can not describe it as well as others who have reviewed this amp here, but I can second everything they have said.  This amp does an amazing job of bringing out the detail...

Great headphones.  I have only had these for a month, but I totally love them.  I purchased them based off of the reviews seen here, so I don't think there is a ton I can add to them.  All I can say is that all the good things you hear about these headphones are true!