Absolutely dreadful experience that cost us 3 hours on the phone with Airbnb and ruined our evening as we had to cancel and move to a hotel at midnight. Not remotely worth the $600+/night price.
First, upon arrival we were greeted with a port-a-potty and bags of trash in the front yard as the front of the building was covered with construction scaffolding. (The host stated that this had only been put up and she didn't know about it until we arrived, but it takes a few days to put up scaffolding so she should have checked.) The entryway and stairway up to the apartment smelled of mold. Once inside, we dropped our bags and went out for dinner - upon returning, we discovered that multiple windows had broken latches and could not be locked, meaning that anyone could climb up the scaffolding, push up the window, and come right in the master bedroom. There was also a flickering light in the master bedroom that looked like an electrical issue. There was old food and a dirty dish in the fridge - gross, and that plus a crumpled towel in the bathroom made us question what else had been missed or left not done by the cleaners. We called Airbnb to cancel and then had to spend 3 hours waiting on a combination of poor Airbnb service + them not being able to get in touch with the host until finally they confirmed the cancellation and we were able to leave (at ~11:30pm) and move to a hotel.
Overall, the place is spacious but furnishings are worn and the interior design sparse. The photos make it look beautiful but the reality is a long ways away, and it is greatly overpriced. I definitely would not stay there again.
On the upside, the location seemed pretty quiet (an hour of fireworks outside was likely an unusual event) with a reasonable amount of road noise, perfect location in Hampstead Heath, and once she finally saw our messages (it took a couple hours) Megan was clearly extremely regretful of all the issues and offered to move us to another of her Airbnbs at a discount. There were no places available in parts of London where we wanted to stay and with shaken confidence in her management we didn't want to risk it at that hour of night so we didn't take her up on it, but we did appreciate the gesture. She did pay for the cost of our Uber to move to the hotel. I hope this is a learning experience for her to appropriately check the conditions of her rentals before guests arrive.
Also - beware Airbnb's AirCover guarantee. Despite it being the literal last minute and the price for places comparable to what this rental should have been being higher than what we had paid in advance for this one, the case manager refused to cover the cost difference which led us to cancel for the refund and default to a hotel. Don't rely on that guarantee.