Alignment was a breeze - the 2nd calibration star was almost exactly in the middle. Polar alignment went well. And then I wanted to take photos of NGC 884 / NGC 869. But somehow I lost the alignment. It was absolutely impossible to take 4 min exposures - they all had star trails. In fact, PHD couldn't correct it enough.
Instead of redoing the alignment, I tried shorter exposures (2.5 min). The result is OK - but I should have rather redone the alignment: