Rooms are clean and spacious, good location being almost right on the waterfront. Staying there recently during low season the hostel seemed close to empty but still met some people while hanging out in their common area downstairs.
One of the best hostels I've ever stayed in! Staff are SO friendly, rooms are clean and comfortable, very social atmosphere and super easy to meet people, loved my time at HI Siem Reap!
Stayed here during Songkran 2013 and it was a perfect getaway from all the madness of the festival. Dorms are clean and staff are friendly and happy to help you (they actually ended up doing all my laundry for me because the machine was busy when I wanted to use it!). There is also unlimited toast and coffee/tea all day which is an awesome perk!