We spent a week at the castle in July in the Salon du Jardin apartment.
Pros: beautiful castle, great view, spacious apartment especially the living room was big and lofty, Celine, the hostess, was very helpful.
Cons: somewhat dirty, the appliances could use an update as many were quite old especially the fridge, we had no hot water for the first 3 days due to a thermostat malfunction (this was fixed though as fast as possible by Celine), bedrooms quite dark and damp/humid, lack of welcome brochure with common information e.g. wifi-codes, laundry possibilities, place of interest in the vicinity etc.
This is definitely a beautiful place and if you are looking for something different than a hotel this is definitely a good candidate. But for our taste, the cons did outweigh the pros unfortunately.