We stayed here for one night as a stopover on our trip back to Kampala from Moshi via Nairobi. We booked through Expedia and the booking went through smoothly to the hotel so they were expecting us.
The staff were attentive and helpful. Our room smelled of smoke from someone smoking in a neighboring room so we asked to change rooms. A staff member showed us another room, which also smelled of smoke as smoking is allowed in rooms and there don't seem to be any designated non-smoking rooms. When we went to move our belongings from the original room we found the smoke smell had gone so we decided to stay. The staff member said he would request the neighbour not to smoke in his room, which we thought was a generous offer since people technically have the right to smoke in their rooms. We didn't have any more smoke smells. 
Bathrooms are indeed tiny as others have said, but manageable. Shower was good and toilet. Plumbing in toilet and sink needed a bit of maintenance, which we reported to the front desk. 
Bed was comfortable although the pillows were quite flat so I folded mine in half. 
Pity there are no fly screens on the windows as we would have liked to open a window to let some cool air in. 
We were very thankful for the fact that the restaurant is open 24 hours because it meant we could have a late dinner after arriving in Nairobi and sorting out our onward bus tickets for the next day, and also have a very early breakfast cooked fresh and get a packed lunch to take on the bus. 
We didn't find it noisy, perhaps because it was Boxing Day and that area of the city was very quiet. 
Others have mentioned the security doors being a bit annoying - you just have to factor a little extra time into getting in and out of the building. It wasn't too bad. The lift was very slow, though!
Over all we found it entirely adequate for a brief overnight transit stop in Nairobi. I think it would have been ok for another night or two if necessary also.