I've used this mixer for around a mounth now, and I'm very pelased. I needed a good interface that works with Linux, allows me to practice bass playing while listening to a backing track, and has separate pots for headphones and line out (I use this for active monitors). This satisfies all those demands, and more. It also works as a recording interface (though I haven't tried this yet). 
 
PROS: 
- Works with Linux straight out of the box (Ubuntu at least) 
- Sturdy quality, all metal housing, small size 
- Completely silent, no hiss or hum 
- Runs on USB power (power supply still included though) 
- Balanced inputs and outputs 
- Hi-Z/line input selector 
 
CONS: 
Only one missing feature: An additional control for panning between channel 2 and 3 would make this into a true 3 channel mixer. Now you have to set the levels at the source, which might be bothersome in some situations.