I've had this for several months now, and I don't know how I lived without it before.
I have this connected by USB to my computer, and the output to my main amp. My second computer goes in the 2 track input, which is fine as I don't use that one for sound stuff, and I have a record deck, through a phono pre-amp, in the line input. This mixer now means I have a good quality, dampened, rotary fader with adjustable gain and two-band EQ for the audio output of my computers and my turntable, and it sits perfectly right next to my keyboard and doesn't take up too much desk real estate. The build quality is also excellent - sturdy and with a bit if reassuring weight to it. Everything can be controlled from once place and I don't need to alter the output volume on the amp much at all. I also now have a headphone socket on the desk front with separate volume control. These features are invaluable to me as I listen to music a lot and am a part time producer. It's really adaptable and I have used it in many different set ups since I've had it.
It didn't cost a bomb, it really couldn't be simpler to set up, and works like a charm. I have never experienced the noise or interference that other reviewers have mentioned, but this could be partly due to the fact that I don't need the gain to be too high as the amp it is connected to is really quite powerful.
This is a great little mixer, packed with excellent features, at a great price. It even comes with a mains adaptor to use it without a computer.
If you want something small to co-ordinate a few inputs, perhaps by USB, at home or on the move, that's flexible and of high quality, then this is the small format mixer you want.