Therefore I have decided for this meat thermometer for 35 Euro.
Positives: The temperature measurement is perfect. Lt. my calibrated infrared thermometers from Fluke even on degrees exactly. The display is easy to read and it can be adjusted simply. It's also nice that the oven temperature display (second sensor in the rubber top of the pen).
Negatives: The quality of the turning wheel is bottom drawer. Wobbles like a lamb's tail, no real snap points when turning, therefore no sense in setting. The socket of the cable is also carried out quite cheap.
The negatives have actually surprised me because I did not know something of Rösle. The offending knob should have noticed that.
I kept the thermometer because it measures the temperature so precisely. Previously I had a meat thermometer WMF, which by 8 degrees and ran next to my roast lightly were still raw inside.