1. Set Your Own Pace
When you are on a tour with a large group, your pace is determined by the slowest member. Unless you are the slowpoke, then that means you aren't going at the pace you want. You can decide when and where you stop. You can blaze by a herd of gazelles and then eat your lunch on a steep cliff overlooking the savanna. You won't have to put up with anyone's whining or complaining.
2. Skip the Boring Parts
Have you ever been in a tour group and the guide seemed to take forever explaining every single detail of a plant's life cycle? Then, when it came to the exciting parts - like the lions and the crocodiles - he quickly skipped over them so that he could spend another half hour talking about the diet of the tree shrew. When you are on a self-drive safari, you won't have to put up with this. You can drive right by the plants and the tree shrews to spend more time exploring the exciting stuff.
Self-drive safaris aren't for the faint of heart. However, if you are a self directed person and you like to blaze your own path, then a self-drive safari can be a rewarding experience that you will remember for years.