Stayed two nights with my girlfriend, one before and one after a 2 day tour to Lençóis Maranhenses. As others have pointed out, the facilities aren't old and dirty. Dinner was horrible and expensive and the wifi wasn't working at all. However, for me the worst part was the extremely bad attitude of staff and their lack of professionalism.
On my second night, I checked in at around 21:00 but as soon as I got to my room I realized there was no running water and I wasn't able to take a shower. I was told there had been an issue with the water pump that the affected the WHOLE hotel, but that it had already been fixed and I should have water in my room in 10 minutes or so. One hour later, there was still no water and no explanation. I soon found out that all common areas (restaurant bathrooms, gym, etc) of the hotel had running water, so I went the receptionist what was going on. Instead of at least apologizing and placing me in another room, the receptionist talked down on me with a defiant tone and told me there was nothing he could do and that I had to be more patient and wait! In the end, my girlfriend took a shower in the gym's male shower while I waited outside to make sure no one would go in (there was no lock and the gym's female shower was broken). By the time we were done and went back to our room, water was finally back (cold water only), but we were already stressed and exhausted of almost 3 hours of fighting with impolite hotel staff.