Unlike some of the other reviewers here, I thought the required bus tour around Robben Island was a pretty good way to get an overview of the site. I also very much enjoyed the former inmate guide we had for the tour of the cell block. He wasn't the most dynamic speaker, but it was still a good experience overall.  I learned a few things on my tour and appreciate the visit and got to see Mandela's cell, but it isn't the most interesting WHS.

 

The whole experience does take a very long time. I understand the need for a boat, but I don't really understand the reason for asking everyone to line up in the building by the dock for so long before the boat departs. This seemed a huge waste of about 45 minutes. There are a few interesting panels and a video playing, but it got old very fast. Then we had to wait an extra half hour for the return boat because one set of passengers was apparently way behind all the rest of us.

My bus guide said this was the only place you could see one UNESCO WHS from another (looking at Table Mountain).  But I read in a recent review here of at least one other place where it's possible (Agra Fort to Taj Mahal).