Let's face it - there is no good reason to spend much time in Johannesburg. When you've gone through the Apartheid museum, the Constitutional Court House, the compulsory but meaningless tour of Soweto (because seeing it and living in it are 2 completely different things), you're done... The rest is neverending suburbs with high security walls... Living there is, I believe, quite nice (lots of culture, nice places to drink coffee at,,,), but as a visitor, forget it!
Having said that, if you have to stay there, the Farmhouse is the place to stay... A beautiful garden - great mix of British and Florentine inspirations, a gorgeous colonial house and outstanding rooms to make you feel comfortable and relaxed after your day in ugly, dangerous and stressful Joburg. The welcome is warm but not embarrassing, the rooms are better than in most 4* hotels I've stayed in, the atmosphere is somewhat perfect - cosy, comfortable, discreet...
Dining was excellent - very cheap ($15 for 3 courses) and enjoyable. Don't expect 5* chain hotel servicem this is a guesthouse, not a Hilton!
What is special about the Farmhouse is not about any specific feature or service, it's about this rare concept of charm. What Karen and her team have achived is creating a place where everywhere you look is beautiful and lovely. All details have been carefully designed and the result is a place where you feel instantly comfortable and relaxed. I felt I could stay there for a long time... and this was a blissful heaven in Joburg.