I had the best time here. Cocomama has the absolute best staff, who are fun, friendly, and helpful. Britt deserves special mention for being a total boss. The hostel has a great location- in a great part of the city, but outside the red light district, so you can sleep if you want to or go out if you don't. Easy access to public transit, and excellent food nearby, for all different budgets. I had a lower one, and I loved a kebab place just down the street.
The other people staying at Cocomama were also enjoyable. Mature, respectful, and fun-loving. This is one of those rare hostels where it's safe to leave your computer out if you so choose (they have lockers so you don't have to, of course!). I must admit that Amsterdam was not my favorite city on my trip, but entirely thanks to Cocomama (and maybe the Van Gogh museum too) I still had a great time. I can't recommend this hostel highly enough.