Pros: Value, sound, build quality, size, volume control
Used with studio monitors and Beyerdynamic DT-990 250 ohm headphones.
Nothing really bad to say about this DAC/Amp. The build quality is high, size is small, it drives all headphones I tested it with well. No flaws in the audio quality, looks good, gives you a volume control not only for your headphones, but for your speakers too which is nice if you use studio monitors with separate pots on the backs of the speakers. It's also worth to mention that it accepts digital input from USB, or optical toslink.
So if you need an affordable DAC with RCA outs and an adequate headphone amplifier built in, this is a great alternative.