Momo was very responsive and informative and there was never a long delay which was very useful.
The apartment is beautiful and very stylish. The towels and linen are all very good quality and the bed is warm and comfortable. The TV is massive and all the gadgets are readily available.
All the amenities you need are there and the information guide Momo has in the apartment is excellent and very informative.
The location is in an up and coming area on the outskirts of the downtown area which is great as it offers a good opportunity for some decent walks into the main areas, but taxis / uber are also not expensive.
See my comments below for more on this. There is also an excellent and affordable Vietnamese restaurant a few metres away.

Some things to note.
If you are visiting in the early part of 2015 be sure to check with Momo on the current state of the building works. When we visited, we were not aware the windows of the apartment would be completely covered which meant no natural light came into the apartment at any time.
If you are using the apartment purely as a base to sightsee then it’s not an issue, but if you are hoping to enjoy a coffee while you look out of the window, then you need to check as to the status of the building works. I believe they are due to be completed Q1 2015.

To elaborate on my points about the location - for any international or first time visitors, the apartment is not in a very picturesque part of town. It is quite industrial and there some homeless shelters nearby so it does offer you a sight of the “real” San Francisco. It still feels very safe as there is a police station/court house over the road ,but if you are looking for the San Francisco that you see on TV / movies then you may need to research other areas.