Really nice, lively crowd at Nana - plastic seats, very loud, but enjoyable (to us). The food is definitely not as good as Khao San's. Not much else to say - we had the tom yum soup and wished it had more flavour . The beef noodle soup was very interesting. Pad thai was my favourite. Chicken curry and beef skewers were good.
I would not wait in a long line for this food, but I would go again if in the area.
Cannot wait for the new Khao San location to open!