I had a great experience because of 3 reasons;
1) Great flexibility! I contacted Dana just 2 hours (!!!) before we wanted to check in and even though availability on the website was not shown on Airbnb for that night she arranged a room for us and replied within 5 minutes!
2) Great hotel service! Besides a cheaper price there is no difference in booking through Dana or straight at the Donatello hotel. Rooms are amazing, very luxurious and staff is very friendly!
3) Best location! Right at Union Square with amazing shops and perfect start to jump on cable car or tram (7 minutes walk) or any bus from several locations right around the hotel.

I don't think you can get a better hotel look and feel anywhere in SF for this price. I can totally recommend it!