I booked 3 nights, and ended up staying 6. It's a good place, the dorms are big, but are divided up with doors so it doesn't feel like there are more than about 8 people in any of them. Breakfast is good, and as cheap as you'l find anywhere nearby. Kai is lovely, really helpful and a lot of fun. The communal area is well laid out and well used, so it's easy to meet people. All round, a good place to be! Oh - only thing - the showers are sometimes warm, and sometimes not. It's a bit random.
I loved my stay here. Samon and all of his staff are wonderful, and there were regular evening games of kick the shuttlecock with staff and guests. The atmosphere is lovely, the food is amazing (and reasonable prices, especially compared to town). I would go back in a heartbeat. The only thing is there seems to be a problem not letting them say it's full - I was only able to stay my first night due to a no-show. They seem to always find somewhere to put everyone, though.
Even though the hostel was hosting a barbeque for Christmas eve, there was no atmosphere to the rooftop bar, or to the hostel. There were no lockers in room 203, and leaving valuable but needed items (camera, money etc) in a locker at reception would have been a pain, especially as in a big hostel there may be a wait for staff attention (not a problem per se, but annoying if you just want to grab something and go out). It's fine, as things go, but I'm sure there's better.
After booking for 2 nights, I stayed for 4 and was sorry to leave. The staff are amazing, the atmosphere is unparalleled and I'll be surprised if I find as great a place in the rest of my trip. It was my travel companion's first stay in a hostel - he was spoiled for ever. So sad. Go there. Go there now. (In case you're reading this, Anni and Phuong - Hi guys! You all rock! Miss you all.xx)
Lily and David were amazing. Hanoi was my first destination, and after my luggage stayed in Paris, they moved heaven and earth (and probably a guest or two - sorry guys!) to ensure that even though they were fully booked, I could stay there another night to wait for my luggage. Lockers in the dorm were spacious and worked fine. The hot water is a little limited by the small tank, so go easy on long showers, for the sake of the other dorm folk! (It does get very hot, though :) )