Actually I found out something interesting: I set the reflection back to lumen and increased the quality to 4.0 and enabled “Hit Lighting for Reflections”. And it looks pretty much as good as with ray traced reflections. (except the mirror maybe).
So what really makes the reflection on glass get bad is setting translucency to raster. If translucency is set to ray tracing then the reflections on glass look pretty good.
I also increased the intensity of the skylight. 0.1 seems good.