Build Quality
By its nature this product has a few delicate parts: the clip, lead and capsule are all vulnerable. In my case, I use the system on an acoustic guitar. The clip is not suited to this purpose, and, although Superlux do manufacture a microphone for this, it's not stocked by Thomann. I went through a couple of clips/microphones before giving up on this, and replaced the (broken) clips with the suckers from kitchen hooks; if there is a glossy finish on the guitar, they stick perfectly well. Both the capsule harness and the micro-xlr connectors have stood up very well, and despite heavy and careless usage, have remained sound.
The preamp unit is also solid and heavy. The battery cover has come off the one I use most, but it works OK without it - the battery still sits snug in the preamp; the switch also works well.
Applications
As well as with my acoustic guitar, I have used this on accordions and fiddles playing traditional music. It's unobtrusive and portable. As a result of using them, three of my friends playing accordion and fiddle now use them almost exclusively.
Sound Quality
Pretty good. They're a copy of a mic system 3 times the price, and look identical. I doubt the build quality or the capsules of the original are in any way different. A/B'ed with small diaphragm condensers I found the noise floor to be a little higher but nothing unusable (at least not for live - for studio I'd use something a bit better).
Conclusion
I've bought five or six of these and will do so again, and would recommend them as a good value solution for acoustic bands.
