The Circus Hostel was a fantastic place to stay, and I'll definitely stay there again in the future. The Rosenthaler Platz U-Bahn station is literally right outside which makes it super easy to get to, and there's also a tram stop right outside as well. When checking in, I was told to go check out the room before I paid just to make sure that I was happy with it which caught me off guard but I feel is fantastic customer service.
The room design is very open with a common area table to sit at, and while you're assigned to a specific room, there are no individual bed assignments. Suitcases and the like don't have any spot for secured storage, but there are reasonable sized personal lockers for each bed which also have plugs inside of them. My room was only on the second floor so I'm not sure about the building as a whole, but I was able to get access to the free Wi-Fi from my room which was a very nice surprise and unlike any of the other hostels I stayed in throughout my time in Europe.
There's a bar downstairs which has very good prices and also seemed like a great place to hang out (I arrived the night of the Olympic opening ceremonies, and the place was packed with people watching it). There's a café right off the lobby just where you can buy food, but there are plenty of other eating options right in the immediate area as well. Being right on both the U-Bahn and tram lines make it very convenient and easy to get around Berlin.
I loved staying here and will gladly go back in the future.