I used the upgrade program and enjoyed the breakfast, all day snacks and access to business room and great time for the light dinner & wine. I recommend this program, even if the room is almost the same, there is a nespresso machine and many consumable.
The breakfast in the business room is good, but after the second day I went to the main one, which was larger. The hotel offers very tasty fruits, great healthy cooking and heavy for those who enjoy strong breakfast.
But the best is by far the fitness center. The Planet Fitness is integrated in the Hotel, at the 10th floor, and there are 3000 square meters of equipment, rooms, huge swimming pool. I used whatever I could, but this is a dream for somebody who likes sport.
Finally the staff is very friendly, I had a late check out included in my upgrade, I left the room at 15:30 and enjoyed the business room until I left for the airport. The hotel has a shuttle to the train station (Sandton) which takes only 16 minutes to reach the airport.
Definitely the hotel to stay in Johannesburg.