Simon's place is a super comfortable, wonderfully clean, cute flat with excellent transport links to central London. My father and I came to London for ten days and it was the perfect home base- it's really is a 5-7 minute walk to the nearest underground station (and then about 20 minutes to the heart of the city on the northern line), and because it's located in NW London, it was a breeze to get out of the city and hit up other areas of interest such as Bath or Dover.
The neighbourhood is quiet but not dead- there are a ton of shops in walking distance featuring everything from kabobs to outdoor gear, in addition to the bigger chains like Asda. It was great to have off-street parking available, but there was always plenty of street parking as well. Even walking back to the flat at half-past midnight, I felt safe.
As for the flat, it's on the second of three floors, and just like the description, features two rooms- an open plan kitchen/diner/living room, and a large double bedroom with en-suite bath. The bedroom has a huge wardrobe, and the bathroom is nicely done with endless hot water. My dad took the bedroom, and I took the sofa in the main room. Alas, it's not a pull-out bed, but rather a 'sofa bed'. While that meant that it was plenty wide and surprisingly comfortable, if you are any taller than me (5'2), your feet will dangle off. Both rooms have lovely natural light, and the kitchen had everything that we needed.
The only minor niggle was that the wifi was at times impossible to connect to, or took 10 plus minutes to successfully log in. Because we were so busy, I did not contact Simon to let him know about the issue. Given his speedy responses to all my other questions, I have no doubt the issue would have been addressed promptly. Prior to arrival, he sent clear instructions on how to gain entry into the flat, the location and neighbourhood, and even offered a couple of tasty pub recommendations as well as tube advice.
We would absolutely stay here again, and I highly recommend it!