I've had this system (including the different add-ons) for a year now. In the beginning I used it as a mic for acoustic guitars, ukulele and so on. And it did an ok job. But the problem was how it was build. The microphone itself does an ok job - and regarding the low price: pretty awesome.
But you can feel it is cheap. The way you put it on the instrument feels unstable - and it keeps falling off the guitar. I bought it cheap because I only sometimes have a need for a system like this (for ex acoustic guitar, sax, violin, ukulele). But I haven't used it for a while - because I don't trust it.
I don't have any solutions, but right now it's packed away and only used when it's absolutely necessary (and I miss some excitement). If it was built better - definitely more stars.