First time Airbnb user and first time in the UK and Penny couldn't have been more friendly and welcoming. Had a great conversation with her, really cool lady.
Her place is lovely and my room was nice and private. The bathroom is shared but the other guests were lovely and friendly as well and there were no problems with it.
Location wise it's a ways out of central London, so even though it takes a while, it's not difficult to get to (the bus stop is literally around the corner from her house).
I only stayed overnight (got in late and left early) but she was very accommodating and I was very comfortable. Would definitely return.