I stayed there for 3 nights in a single room with a single bed. The room was very clean with bright white sheets and a good AC. I booked over booking.com and payed €13 each night.
I can really recommend the little Cafe located right next to the Hostel and I am a big Coffe drinker.
Also the massage place next by is really good. I had an hour neck and back with oil for 250 Baht and even though the location feels a little strange in the beginning it was a wonderful one! The laundry place right across the street is really good, too.
The hostel is in the middle if everything bit really quiet.
Just one thing: they didn't make my bed or changed the sheets in 3 days. It didn't bother me and I am sure if I would have asked they would have done it right away!
Go there when you are in Chang Mai!