I did my first DGT with Mountain Backpackers, it is actually a really good option. Considering what you’d pay to hire a guide for the same hike, their membership fees are very reasonable. They usually allow MCSA members to join as well. Their requirements for who is allowed to lead a hike are very strict, and more so with the DGT.
Don’t take a DGT lightly - there is a lot that can go wrong on one, and knowing what to do when things start going wrong is crucial. Not one of my DGTs has gone entirely according to plan, all have included periods of time in thick mist and 5 out of 6 completed DGTs have included something relatively major going wrong - near lightning strikes, caught in massive storms, someone in the group getting sick, early stage hypothermia etc.
The Drakensberg is a remote location, unless something goes wrong near Sani or by the start or finish, you are somewhere between 5 hours and a full day away from help. If you need rescue, assuming good weather so they can get in via helicopter, they will still take a few hours to get to you. If its windy or cloudy - it could take considerably longer. It is therefore very important that you are prepared and know how to handle situations as they arise.