Really wonderful hiking route, I did it in mid October when the weather was still warm and sunny. Dont expect to be alone on the trail, you pretty much always see people ahead or behind you, but the it was not too packed either. The elevation is very modest, I saw people of all ages hiking. If you are a seasoned hiker than this will be a piece of cake for you, if you are a rookie then you still can do it without too much pain.
You need to buy a parking ticket in Einruhr if you'd like to leave a car there, but if you drive up the serpentine towards Kesternich then you find a free parking lot just about 500m from Einruhr.
All in all, its a fantastic route, I'm very happy that I did it.