Bought a pair of these Haun MBC660 several years ago and have already used them in hundreds of recordings.
They're very well built, heavy and sturdy.
The sound is clear and maybe a bit lacking in LF response but very well balanced and apparently remarkably flat above, maybe, 400Hz.
Very nice mics for acoustic guitar, mid-frequency percussion or instruments where you need to capture fast transients from up-close.
They're not too sensitive so i wouldn't recommend them for Nylon strung guitars if farther than about 1 meter.
Not advisable for orchestral overheads or ambience also due to the fact that they're not sensitive enough and, being cardioid with a tight lobe, they tend to loose LF sensitivity with the distance.
Also, not suitable for horns or vocals because the diaphragm is very close to the front grill and extremely sensitive to wind.
Do not use outside! Wind will ruin the sound of these mics.
They excel in a very good way with steel strung acoustic guitars, snare, toms, traditional (world music) percussions and i've had good results with them on large Choirs captured from about 4 meters.
If you're considering buying these i recommend a pair. They're great for Stereo work and Haun seems to have very stable manufacturing specs.