Metz have made a very solid and clean looking flash unit. The 'Made in Germany' moniker is stamped proudly below the flash head on the rear of the camera, and anyone familiar with German manufacturing techniques will know that this is essentially a stamp of quality. Everything works just as it should, and nothing is loose or badly fitted. The flash fits securely to my Nikon D90 via the twist collar lock, and I have had no problems with maintaining the electrical connection between camera and flash.
The only complaints I have, in terms of build quality, are small. The battery door is a little stiff to open and close, but this may get better over time, and the power button on the back of the Metz 48 could be a little more positive with its on/off action. I have had no problems with the power switch, it just could have been firmer, in my opinion.
Everything else works exactly as it should. The auto zoom quickly and quietly finds its range, the tilt and swivel head works great, and the flip out reflector and diffuser are easy to operate.