This is a versatile little device with good sound quality given its price. I bought it to record band practices, but I've actually found a ton of other uses for it, using it to record gigs, as a field recorder, and even to record a drum kit for demo tracks.
Build quality is decent. It's all plastic apart from the grill, but it's acceptable. The important controls are available as buttons or dials, so it's very easy to use. Lights on the top indicate when its clipping, so you don't have to be constantly looking at the screen.
There is the option of Mid-Side(MS) on one side or XY on the other. MS lets you set the stereo width while recording, or even better, set it to RAW mode and fine tune the width later on your computer using a MS VST plugin. You can also choose 4-channel mode which records both MS and XY simultaneously to two separate stereo tracks (albeit with a shared preamp gain). When recording band practice I set it to 4-ch mode and place it in the middle of the room. Then when I get home I can balance the four channels on my computer.
There's a line in (it takes the place of the XY mics), you can monitor the recording with headphones, there are some basic compressor/limiter/filters, it has a tripod mount - the list goes on. This thing is amazingly good value.
The only downsides I've found are that it could do with an input pad as it's too sensitive for loud environments; I'd prefer the record light on the top; and the internal clock is poor, so you may have to spend a bit of time stretching and syncing if you are using it to record audio for a video or to be used in a multitrack mix with other audio.