I stay at Baan Chart at least twice each year, usually three times or more. I love how close it is to Khao San Road. It's less than a block away from Khao San but without the noise. There is still some street noise but nothing like Khao San.
The staff are usually friendly and typically greet me with a welcome drink. They are usually quite accommodating about special requests (I always request 3rd or 4th floor, closest to the street) and late check-out, as long as you make the requests when booking.
Like many places, you have to give a 2000 thb cash deposit at check-in, which is returned upon check-out, assuming everything is good with the room.