It was a great stay for us at the Lisboa Arte Hostel. It's a really small Hostel in a great neighbourhood with bars and restaurants just around the corner. it's very familiar and we felt welcome from the first minute. We stayed 3 nights in the here announced 4 bed dorm but it had 5 beds which didn't bother us since it was never fully booked. The rooms are simple but clean, it can only get a little bit noisy during the night.
We totally recommend it to any body who looks for a pretty place to stay in Lisboa!