First of all, I'm sorry to write in English but I'm afraid that my German is not good enough to write a full review.
We had a very pleasant time in Holzerath. The hosts are very friendly and helpful, even if our German was less than optimal to explain the questions.
The house is nice enough, but the garden is the cherry on top. Our young child had a great time walking around the garden and admiring the tomatoes and fountains.
With the blinds it remains relatively cool inside even with the scorching temperatures outside.
There are two small drawbacks, the first is the relatively low ceiling at some places. If you are a tall person you have to be a bit more careful. The second is the amount of cutlery, especially the amount of kitchen knives and larger cutting boards.
The interior is a bit old fashioned, but that is clearly visible on the pictures. Furthermore, the town itself does not have any grocery shops, so you have to travel a bit further for food. However, the upside of living in a quite place that there a multiple wonderful hiking roads starting right at the doorstep.
All in all it is a nice place to stay with friendly and helpful hosts.