If you plan to stay here for more than a week, you will be paying more than the price quoted on airbnb. At the very bottom of the page, it mentions that they charge a fixed rate per unit of water and electricity. Given the heat in Bangkok and the convenient air conditioning in the apartments, you could easily have to pay half of your rent in utilities. In my experience this is rare for airbnb--having to pay outside of the actual reservation. My stay was for 33 days, but I was here less than half the time of my lease because I traveled around the region. At checkout I paid 1900baht. And, I did not run the AC much. So keep in mind that what you agree to pay now, is not what the rental really costs, unless you are staying less than a week. There is a room on each floor where you can find the meters for water and electricity, I suggest you find these upon arrival, so you don't have to worry about what else you will be paying upon checkout.
Besides the ickiness of having to still deal with money and people (which is why AirBnB is so great!), I really enjoyed my apartment. It was clean and comfortable. There was lots of closet space, a nice desk, and a nice sized mini-fridge (which I unplugged because I was super paranoid about the electricity-and it's the only thing in the room that runs whether you are there or not). I used the laundry room and enjoyed siting by the pool, which feels like a mini oasis in the sea of urban Bangkok. And the restaurant and staff were really great, I ate several meals there. I was always happy to get back to iSanook after my travels.
Taxi's can never find the place. I had iSanook send me the address in Thai as well, but my phone scrambled the Thai script. I finally got a local to translate it and write it down for me and the taxi drivers still didn't know where it was. Also, they say to just call the desk, which is great if you have a phone that can call in Thailand. Because if you don't the taxi driver will also claim to not have a phone. So I advise that you get that figured out really early. Taxis here are cheap, so nothing should stop you from taking one.
iSanook is a great place to stay. It feels really western and modern. But read the "fine" print. Utilities are not included in the price. Where I am from, if you have to pay utilities, you sign up with the utility company yourself. Checkout iSanook, but keep some of these points in mind.