Palacio Sant'Anna is a well located accommodation in the center of Lisboa (by walking it's 5 mn to Av. da Liberdade - 5mn to Martim Moniz - 5mn to Rossio. So perfect, but you need to like climbing because the palacio is on the top of a hill).
Also the area is nice and with few tourists. So it seems more authentic than Baixa Chiado, Rossio, etc...
All the people working at Palacio Sant'Anna that I met were very kind.
Some students live there for a semester, and the other rooms are rent for short stay. So it's an unusual environment, but also a great opportunity to meet some persons living in Lisboa for several months.
On the ground floor, there are some bedrooms, one studying room, one living room, the biggest kitchen and toilets, as well as the showers (men/women separatly).
Then, all the other bedrooms are on the 2nd floor, like the room n°32 for instance. On this floor, there is also smaller common areas like 1 kitchen and 2 toilets (one for men - one for women). All of them are usually quiet, clean and convenient. Still, it looks more like a calm student residence than a hotel, with all its advantages and disadvantages.
The size of my room was big enough. The view is really nice. And the furnitures simple but ok. The only thing is that this one is next to the kitchen, so it can be a bit noisy depending on who is in there to cook.
But all put together, it's a really good choice regarding the price and the environment, so no regrets at all !