I booked Casa Maria B&B after seeing the highly rated reviews.The price is good, and it's located is in a nice area 20 mins walk from the train station, and the owner was friendly. The first night the hot water was not working, barely a trickle of cold water in the shower. The owner did come to look straight away, and he said it would work eventually. It didn't, so the first night I had a cold shower. He did get it fixed on the Monday. Also the Internet connection was slow and intermittent. On check-in the owner said he couldn't do anything until an 'expert' would fix it on the Monday. I guess that never happened, as it remained slow the rest of the stay.
The two sofa beds were quite uncomfortable, and the apartment was in need of an update. The photos on the website are misleading (I guess the rooms in the photos were somewhere else).
If you're on a tight budget, this might be an OK option, but there are better places to stay.