I now possess already the third taillight of this series within a few months. As with other cyclists, the parking light is now broken once again. Luckily I have a bike dealer who uncomplainingly exchanged the lights and over again to send a contribution of BM ("Until it understand ..."). Weak.
The backlight itself is good, the mounting somewhat difficult.
Addendum of 12/11/2012: In the meantime, BM seems to have gotten the quality problems under control.