I think it should be made very clear that this flat is on the 4th floor with many, many stairs in a narrow hallway. If you are older, unfit, or have heavy luggage, this flat may not be for you. It was pretty gruesome getting up and down the stairs with my heavy suitcases. If you are on very tight budget, this small studio may work for you; however, if you can shell out a few more pounds, I would perhaps stay somewhere a bit more upscale. This is a very bare bones flat. I did feel that the flat was not as clean as it was advertised to be. The walls seemed like it could use a good scrub or a new coat of paint. There were multiple hairs from the previous guest on the pillows and sheets when I arrived. The bathroom itself is fine, except the water pressure is extremely low and the temperature is tricky to get right. The bedroom walls are very thin and I heard my neighbor snoring or talking the entire night. The flat feels like you are living in a college dormroom.
If you are not technically capable, the Klevio key could be a bit of a bother. I wish I just had a pair of actual keys for the flat. And the warning that the electronic key would stop working at 11 am sharp was a bit impersonal to me and did not feel very welcoming.
The good is the location, which is in Notting Hill and it close to the train station. Again, overall, if you are extremely budget-conscious and don't mind these things, then go for it.