Great location (near St Pancras), fairly comfortable beds... overall: good value for money.
The downsides: check-in process didn't go smoothly, we had to wait a long time (1h) after the planned hour (14:00) because the apartment wasn't ready, and it was a super hot day (30+C) Also, it was not well described beforehand.
The bathroom is super small, so for a larger/taller person it could be an issue.
The metro/underground is right below the apartment so you can hear/feel the trains (although that didn't disturb us at all!)