Of course Johannesburg is as busy as you'd imagine. Street vendors giving you their "best price" at your car window, chaotic taxi drivers, human traffic intermingling with vehicle traffic on busy main roads. South Africans are also quite jovial and will have what will sound like "shouty" conversations with one another while they walk to work. I've heard Cape Tonians refer to Johannesburg as the Wild West. I'd have to say that that's taking it way too far but if you're from Cape Town where life is like a constant slow breeze (actually gushing, cold winds) mingled with Bob Marley and flip flops then perhaps anywhere else sounds like a buzz (just jokes Cape Tonians ;-) no harm intended).
But if you step out of the hustle and bustle of Jo'burg you'll come across beautiful landscapes. Here are just a few pictures of the area called The Cradle of Humankind. A paleontological site where great scientific discoveries in the quest for the origins of humankind have been made.
This is a mere 15 - 20 minute drive from my house.