Usually I'd say 2.5 stars. It's not completely poor, but below average, because there are a lot of things to fix.
1. Mesh is completely messed up in Turn #1. Whenever you enter that corner, you are able to see all the holes within the curbs.
2. There is a car eating hole in the ground after Turn #11. Check this out:
https://youtu.be/-ldJqsh5oJY
3. You really dont wanna use the Freecam and take a look around. Espacially the area "Fahrerlager" at the right side of the starting grid.
4. Substanding and similar apps are unable to calculate the proper distance between the cars. Last race I had a car right in front of me, and according to Substanding it was between 15 and 30 seconds ahead.
Unfortunately this exigent track hasnt been improved for a very long time, and I highly doubt those issues will be fixed someday.