I stayed at Patsy's place for a weekend following a work trip. The location was incredibly convenient - close to St Pancras, the tube, and plenty of cafes and pubs, but still on a quiet street. There was plenty of space in the room for me to put my (fairly large) luggage, and the bed was really comfortable. And the value for quality is really fantastic, especially for central London! Patsy was a great host and very friendly.
The only FYIs I'd share (which weren't an issue for me at all during my stay): As other reviewers have mentioned, this apartment is on one of the top floors of a walk-up, so that's something to keep in mind if you have lots of luggage or heavy bags. Also, the drapes in the bedroom are on the sheer side and let in some light at night. I had no trouble falling or staying asleep despite usually being sensitive to that, but it's something to be aware of if you're the type who wants a room with heavier curtains.