We stayed as a group of 9 friends for 2 nights at Bulldog in a private dorm room. The best asset of Bulldog is the unbeatable location right in the centre of Amsterdam, only a few minutes away from main station, coffee shops, red light district etc.
Staff is super friendly and helpful and there is free delicious breakfast included. There is a coffee shop just next to the hotel and smoking is allowed in the cool lobby/bar area of Bulldog, which is also a good place to meet people. Room size is good, cleanliness is perfect and in our dorm there were two combined shower/toilet facilities available. The only thing where I think Bulldog could improve is the design/atmosphere inside the rooms.
To sum up, it's a safe bet and I would totally recommend this place. Thumbs up!