It's cheap, so you can't really expect anything spectacular. As far as ease of use and functionalities, I have no issues with the device. I recommend you use stereo-XLR for the input if you have the AUX outs in you mixer to provide stereo - it'll make a big difference when playing.
The biggest issue I had with these (I bought 3), is the headphones port. It seems it's not very high quality and you can easily get issues if your headphone jack isn't quite in that one perfect position (which will be especially difficult if you have this mounted on your belt for example). I use it stationary with extended headphone cable.