I stayed at Peri's place for 3 weeks and it worked really well for me, beautiful area, super close to the tube and all sorts of shops and restaurants, Hampstead Heath in walking distance, lots of different options nearby, ideal for my needs.
The flat was great for me as a solo traveller, lovely modern bathroom and small kitchen with all the basics. Nothing missing that I needed, cute furnishings and nice high ceiling. Plenty of space for me to spread out but it is definitely a studio size place.
Peri and her parents were extremely helpful and friendly and came around asap when I had thought I locked myself out but it was just my own stupidity.... Contact and communication all good, Peri was a lovely host.
Only downside is that if you are tall you might have difficulty with the loft bed - I'm shorter than average and could just sit up in bed without hitting my head so it was fine for me. Also if you like a lot of privacy, the window looks directly out onto the street, but I had the windows open all the time and it was very quiet and safe so not an issue.
Would happily recommend.