A great experience. The flat was well appointed and well kept. Everything was clean and orderly when we arrived. The neighborhood is great, two of our landmarks for directions were a Ferrari and a Lamborghini dealership, that kind of tells you about the neighborhood. Within two blocks there was a great butcher, a coffee shop, a corner store, a pub and multiple restaurants. Of note is that the unit is a basement apartment, not ideal for anyone that has trouble with stairs. There are 1.5 bathrooms, but strangely the second bath shares a wall with the full bath, it was still helpful with two kids to have the second bath.
Transit was easy, there is a bus stop two blocks away and three tube lines that are about a 10 minute walk. We paid for a black taxi to and from Heathrow, it was 51 and 55 pounds respectively. This was much easier and less expensive than going anywhere near Paddington. The tube will take you close, but would be a nightmare with baggage especially during the day during the week.
Pros:
Really nice neighborhood
Very quiet street
The private park out back was perfect for our kids to run around
Kitchen had everything you need including some seasonings and cooking oil
Quick help from Alex (water heater stopped working and he and a technician had it fixed in less than 6 hours from when we called him)
Little amenities were there, i.e. voltage converter, phone charger, book on travel with kids, etc.
It felt large and bright for being a basement flat
Outdoor table was nice for breakfast in the mornings
Cons:
Smaller bedroom was loud in the morning when people leave for work (it's directly under the main building entrance and the door slams above you)
There was 1.5 rolls of toilet paper (we booked for a week with 4 people)
No shampoo
In fairness Alex thought there was more TP and we didn't mention the shampoo, we just went out and bought them at the corner store.
We would happily book with Alex again.