Firas' apartment is in a truly incredible location. You're a short walk from Gloucester station which is quick access on the central line through to Oxford Circus. More importantly, Hyde park, The Victoria Albert, The Science museum and High St Kensington are all a short walk away.
Be prepared for 6 flights of stairs, though. We had a lot of luggage so it was a little challenging but manageable.
Firas' was extremely responsive and eager to do what he could to make sure our stay was comfortable.
The only difficulty we had was that the apartment was very hot during a particularly hot part of the summer, but I'd expect that to be fine generally if you aren't in a heat wave.
When we arrived we did have to purchase dish soap, dishwasher tablets and hand soap, but otherwise the apartment had everything you could need from the get go.
The fridge and freezer are sizeable, perfect for a longer stay. The internet was also quite decent, I was getting speeds over the Wifi of around 60/20. It's worth noting though that there is no router in the apartment, in case you wanted to connect directly via Ethernet cables.
All in all a good apartment, well kept in a stunning location.