Proceed with caution is my advice for this apartment. The location is great but that is about it. The pictures oversell the unit itself, nothing terrible as such about the unit but certainly the photographer did a nice job. My biggest problem with the unit was the fact that even though it is listed as being non smoking, upon arrival it stank of cigarette smoke. When I asked the person who let us in (not Karim, but his cleaning lady - this is because Karim doesn't actually seem to live in London) - she said it smelled that way because she was smoking in it.
The other issue, which compounds any problem that you may have is, as I mentioned above, that Karim is not present to deal with any issues that may come up. He was certainly not able to help our situation and did not maintain appropriate standards in his apartment for paying guests. When we raised the issue about the cigarette smoke (which was a serious one for us as we were traveling with a 6m old baby - a fact that Karim was made aware of at the time of the booking) - the cleaning lady very "graciously" offered to spray air freshener. When I texted Karim about this - he offered to have her clean the apartment again....by spraying air freshener. NOT OKAY!
I will wrap up by saying this...I have been an airbnb host and have used it to stay in multiple cities - often with hosts who aren't present. Never have I had an experience like this. It's ok if you aren't there (I suppose) to help your guests but it isnt ok if you can't assure that proper standards are met. It is even worse when a problem is presented which causes your guests inconvenience and you aren't equipped or willing to address. In this case I requested that given the circumstances we couldn't stay at this apartment and that he should refund us the booking fee - a request which Karim refused. Again, proceed with caution - there are other options (like the wonderful flat we ended up staying at) in a city like London.