Just stayed for 3 nights - and for the price booked a suite! Just 1260 baht a night. The hotel is very Thai (little English language)and quite basic but the room was clean and bathroom and sheets, towels very clean. Staff really nice.
The suite consisted of large bedroom area with King Size bed (hard mattress), and large bathroom. Plus lounge area with full lounge suite and television with cable TV, small fridge and 2 free bottle of water daily. WIFI internet in the lobby for 50baht for 128 minutes. There is a sunny pool which looked well kept.
Breakfast was not satisfactory at all, but not wishing to cause a fuss we ate elsewhere. ie: Cold toast, no juice, cold fried eggs and floating ham slices! The restaurant caters for Thais and the Thai breakfast was also served in cold bain maries.
Right in the middle of town you are handy for all facilities, post office, restaurants, local goods market etc.
I would definitely stay again.
We were using self drive but it is worth noting that the airport is 30klms from New Sukhothai. There are guest houses closer to Old Sukhothai but we prefer to be able to walk out and about in town.