The flat was exactly as the pictures showed, large and very clean. Had a modern kitchen and beautifully updated bathroom. The location is excellent for access to Borough Market and south bank, 3 minute walk to London Bridge tube and train station. The flat is right beside the train (at the bridge level) and there were lots of trains during the day but it was not intrusive and did not bother us at night (bedroom is very quiet as its on the other side of the building and street).
Pass the Key was very responsive, (even at 11:30pm) especially when the check-in instructions were missing a code (there are 2 and we only had 1 code) and the door description/pictures needs updating. We also had some trouble with the digital thermostat settings and they tried to help.
Overall it is a clean and large flat (a little austere (ie tile floor, no carpets and could use some more furniture)) - we would stay there again.