I have given this four for the amazing location. If you are going to stay in the Camargue I highly recommend staying in a private farm/mas. I think its the only way you can get a feel for this remarkable place. HOWEVER there are what people might think of as very serious downsides to this so I am going to try and explain.
1. This is a working farm so its not a hotel primarily focused on looking after you. We were in one of the cottages 'the berger/shepherds one' which was very cute but also run down. The shower tiles were cracked etc, the bathroom wouldnt meet some people's idea of spotless and the bed had seen better days. However, I dont think i would have wanted to be anywhere else. It was wonderful to hear the owl next to the window in the evening and to wake up and look out and see the black cattle with the white egrets on their backs through the morning mist.
2. You can go out on a ride around the estate and the etang de vaccares which, if you can put up with a young girl yelling at you not to pull on the reins, is a lovely way to see the real camargue and much more preferable to the rides which you can get along the main 'strip' road into Saintes Maries de la mer.
We loved our stay here, we felt we really experienced a real working mas in the camargue which has been in the family for generations, but someone who is concerned about cleanliness and a hotel-like service will probably absolutely hate this place.