The wifi is usually very good.
There is a free shuttle every hour to Sandton Station and Mandela Square, from 6am to 11pm, which is very convenient. You also can go to Sandton City Mall from Mandela Square. If you do not want to wait for the next shuttle, I suggest to use Uber from your phone. The ride to Sandton Station is about 25 Rand. You can get free internet in Sandton City, AlwaysOn.
Just around the corner from the Park Inn hotel, there is a strip center with a few restaurants and a supermarket.
I wish that the standard room had a little fridge and a microwave. But this only would improve the experience. I recommend this hotel in Sandton. From my point of view, good value for the money I spent.