If you were to stay in a budget hotel, this will be a good option for you.
Clean but small(some mentioned long ago it is about 15m2) with all the things you need. Close to Santa Apolónia train&metro station. Not far from down town and castle.
One thing others also mentioned, it can get cold at night. I understimated it.
Turn the heater on when you are back in the flat at night till you sleep to warm the air up.
Ana was great. Communication was tiptop.
When I went there around 6pm, she was waiting for me(ring a bell, I didn't know what to do, so I pressed the bell of No.1, then she came down)
She did even let me check out at 2pm. I left before though. It was very nice of her. Thx!