Great location right opposite Caledonian Road tube station which is on the Piccadilly line. We were only a few stops from all the main attractions, plus one stop from King's Cross St Pancras which would be good if you were coming in to London via train or Eurostar.
The flat had everything you need (enough crockery, hair dryer, ironing board, drying rack etc) to make your stay comfortable. The shower was very powerful & the heating was good (so good that we had to turn it off because we were so warm). The mattress was memory foam I think & I found that very comfy. However, the duvet felt a little small for the bed (but this is a small niggle).
One negative was the noise from outside which is obviously out of our host's control & understandable in central London. However, worth taking into account if this will bother you - mainly just traffic noise at night but there were some occasions when people were shouting outside in the early hours.
Over all, a comfortable flat in a super convenient location!