I only gave accommodations "good" because they're under renovation right now, but the new stuff is really great! Comfy bed. There's a lot to do, lots of activities and tours, but not during the off-season, so go during the right time. Make sure to read the rules carefully so you avoid fines. The staff weren't always there, and there were limited check in-out hours, so plan coming/going carefully. I loved the atmosphere and location, and wish I could see the finished product when it's remodeled!
There was one power outlet for a 12-bed room, and no outlet in the floor's one bathroom. "Breakfast" meant two pieces of bland white bread and some jam or Nutella. There were no lockers to put things, and my stuff got moved around by my roommates. It has an old, rickety feel, and it smells bad. The staff were nice, but sometimes made off-color comments I felt were a bit too personal towards guests. On the plus side, it's right by the museum district, and several lovely parks, and it's cheap.
A bit out of the way, but easy to reach by metro. Be sure to note the directions on their website. Lots of in-room storage, including a locker. Best hostel kitchen I've ever seen, plus grocery stores close by make up for no breakfast. Very fun, girly atmosphere and a large common room with lots of games, books, and movies. Great place to stay if you want to relax in the evenings after a day visiting the city. Also, the staff were helpful and treated the guests like their best friends.