My overall impression is Sochati House in Nairobi City is a nice place to stay. I was booked in here by a friend who recommended it.
It's got nice setting - lush gardens and you wouldn't know you were in a capital city. The staff was really good.
The staff and location make it worth it - but ring before booking to see what the latest is with the hot water!
PS Their wifi is good - once everyone had gone to bed, I managed to get a video link on skype to my other half back in the Uganda.