Pros: Very noticeable SQ increase on high impedance 'phones, bass boost switch, nice look, budget-minded, great costumer service
Cons: Enclosure is not the sturdiest thing in existence (what would you expect)
A fantastic product, JDSLabs make some great CMoys, and the bass boost is fantastic from my point of view. Some may argue it is a bit muddy at higher volumes, but I rarely noticed it to an extreme extent, and even when I noticed it a bit, I remembered how cheap the amp was (also, never forget you can turn off the bass boost). If you don't like the "hipster-ish" look of it, or don't trust the enclosure, I know tons of people bought $10 enclosures and fit them in just fine. I'd recommend this in a heartbeat.
Notes: Used with DT770 Pro 250 Ohm