We had a fantastic time at Rufus's place. The apartment is spacious and has all the amenities you need for a smooth, problem-free stay. Rufus and his support team responded very quickly and comprehensively to all of my inquiries.
I was there with my family (wife and 2 kids ages 5 and 2) and the apartment is very kid friendly. A crib was not available but we brought a pack and play, so that wasn't a big deal.
The absolute best thing about the apartment is the location. Many places advertise that they're "steps away" from the key attractions but it's absolutely true here. It only took a couple of minutes to walk to Westminster Abbey, Parliament, Big Ben, Buckingham Palace, Victoria Station, etc. Trafalgar and Piccadilly are also easily walkable from the apartment. The St. James tube stop actually is just around the corner. This was one of the best (maybe the best) apartments I've stayed in from a location perspective and I will try to book it again next time I travel to London.