If you're looking for a budget-friendly option that offers more privacy and amenities than a hostel (wi-fi, TV with cable, a small refrigerator, the option to make your own tea/coffee and maybe a simple meal), this may be a good option for you. The host was generally responsive, helpful, and friendly, and the Airbnb is in a good location that made it easy to get to major London sights and Heathrow Airport. It was fairly quiet, and a large fan made the studio bearable in a London heat wave.
That said, I wouldn't describe the studio as "outstanding". The photos weren't up to date, and we found the photos to be a bit more flattering than reality. The bed frame and rug are different than pictured, and a few other pieces of furniture were switched out for an additional chair and ottoman-like piece of furniture at the foot of the bed. There are also a few uneven floor boards, a loose bathroom tile, a small amount of bathroom mold, etc. The toilet remains a problem and does not flush well (earlier reviews mentioned this). An increased attention to these details would go a long way in improving the space.
We knew there would be stairs but didn't realize how many! There are probably 80 or so. The climb is difficult if you have lots of luggage, or at the end of a long day.
This could be a good option for you depending on your travel preferences and priorities, but we wished we had chosen to spend a bit more to stay somewhere else.