Stayed in a four bed dorm for 2 nights on the second floor.
The dorm room was very "cosy". There were four custom built bunk beds and a locker for each, taking up about 80% of the room. The beds were solid and comfortable. Normally I get woken by bunkmates shaking the bunks, but here I got some of the best sleep ever in a hostel.
The room didn't have AC, but it did have a fan which was surprisingly effective during the heatwave. The windows of the dorm room had a window looking out onto Rua dos Correeiros, is busy street with many cafes and restaurants. It did get busy and noisy as the window was kept open because of the heat. Although by late evening it's quiet enough that I didn't have any issues sleeping.
The toilets and showers are located in the same shared bathroom, which seem to be cleaned everyday. The showers were quite spacious with racks and hooks to hang your stuff while taking a shower. The showers had wooden planks for floors, no chance of slipping on those like you would on tiles.
The hostels also has a dining area, a lounge and a kitchen on the first floor. All of which were clean and comfortable. I didn't cook, but others did and looked like it had all the required utensils for cooking. I did use the microwave though and that worked great.
The location-wise, the hostel is right in the centre of Lisbon close to all the main sights and transport with plenty of cafes, restaurants and supermarkets around for food.
All in all, an enjoyable stay.