I stayed here for a week. It was generally nice, and the breakfast was excellent, but there are a few shortcomings. I'll start with the good: The rooms were clean and generally comfortable. As mentioned earlier, the breakfast was very good (if you like an English breakfast). The locations is near a few businesses, and may be easy to be around to find a spot to eat, shop, work, etc.The staff were all very friendly, although the maid was a bit militant to clean my room at 10AM (after a night of long drinking, I did not want to get up - she insisted she had to clean the room now).
The bad: The rooms were basic and lacked details that make a place "nice" to stay in. I did not have heating in my room (a colleague had a heater in his room, but the bathroom window did not shut all the way - negating much of the heater). Like some other smaller B&B's the place is dead after dark, so if you want something (meal, drink, service) you may be out of luck. My power went out for a day, but I was moved in to a nicer room after several attempts to fix the lights failed.
Over all: Not a bad place to stay. I would say that if the location, price, and availability work out in your favor, go for it. Otherwise, you may be better off doing a little more homework on a place to stay in Joburg.