I've stayed at the Southern Sun Mayfair 4 times for work. The rooms are comfortable and quiet, the staff professional, nice and responsive. The breakfast and gym are good.
Even though the hotel is very nice, the rates are a bit excessive for what it is (USD299/night). Also, the dinner menu is a bit limited (especially if you're a vegetarian), and the water bottles provided are ridiculously small (and wasteful).
I would definitely recommend this hotel, assuming your budget allows for it.