In many ways, this trip was way out of the norm for me. I'm not exactly a prissy girly-girl, but just from reading the trip description, there would seem to be way too much "roughing it" for my usual taste. But weighing that against my desire to see these places, I decided I could handle it. And I can tell anyone who might hesitating for similar reasons that they should go. Yes, there's a whole lot of the great outdoors on this trip, but in the best possible ways.
I never stopped being amazed by the ever-changing landscape. You see everything from craggy, misty coastline to wide plains covered in scrub brush to mountains to pine forests. And it seems to change completely at least once an hour. I've never seen such diversity over such a relatively concentrated space.
The shine never wore off of seeing the different animals, and not just in the game parks. You never knew when you'd see a monkey on a fence post, or an eagle overhead, or zebras in a field. Then once you're in the game parks, it intensifies. Every bush could be hiding a rhino or some brightly-colored bird, and every bend in the road could reveal a pack of African wild dogs or a lion napping in the shade.
In terms of optional activities, I would definitely recommend doing as many game drives as you can. We had good luck seeing animals both on sunset and sunrise drives, though the big cats were limited (we saw two lions and no leopards).
My friend and I did four optional activities of note. First, we flew into Jo-Berg and took the Premier Classe train down to Cape Town to join the group. That was a fascinating experience, as most of the other passengers were not foreign tourists, but rather people from South Africa returning home to or visiting friends/family in Cape Town. All of your meals are provided, and it's a comfortable way to make that journey, if you have the time. (Note that the train station in Jo-Berg is in a terrible part of town, so be careful with your transportation there!)
Second, the township tour in Cape Town. They can arrange this to suit your schedule, so it's possible to do a Robben Island tour in the morning and the township in the afternoon. The guide they recommend is a young man who's involved in several projects in Langa, and he offers wonderful insight into an area that I knew almost nothing about. That tour completely changed my perception of townships and was one of the most fascinating and rewarding experiences on the trip.
Third, we did the tree canopy tour in Tsitsikamma. Our guide said it wasn't one of the "Weeeeeee!" type of tours, but it totally was. It's an excellent chance to see some incredible birds and learn about the various trees and plant life in the area. You're always secured to something, with three safety lines when you're on the cables and with two on the platforms, so it feels very safe.
Fourth, diving in Mozambique. It was an interesting experience, but not because of the diving (which was dreadful due to poor visibility). You have two options, diving in the lagoon or in the ocean, but the ocean trip requires at least four people or payment for that many (650R per person). The dive shop has good gear, and the people are quite nice (it's currently owned by an American ex-pat). However, even though I had fun, I can't really recommend it. The boat they use is a rubber pontoon-type of thing, and getting back in requires launching yourself up and being dragged the rest of the way in (I was covered in bruises afterwards). The lagoon sites are also covered in sea urchins, which, when combined with the terrible visibility, makes diving there a tricky proposition. If you do want to try the diving, go for the ocean. It's supposed to be beautiful.
One of my concerns when I signed up for this trip was the hiking. The pace of this trip is listed as "leisurely/moderate," but one person's moderate is another person's death march. The hiking was not at all bad. It was never required, so you could always sit it out and/or ride the truck to the end point. I had my concerns about the day-long hike in the Drakensburg, but for me, that ended up being one of the highlights of the trip. It is mostly uphill on the way out, but it's generally quite gradual. At its farthest point, the hike becomes a more complicated and strenuous scramble over rocks, but it's easy to sit that part out (which I and several others did). The views on that hike are stunning, and it felt wonderful to walk after so much truck-sitting. If the weather's nice when you're doing the hike, it's likely to be pretty uncomfortable for part of it, because you'll be in direct sun. We got lucky in that regard because it was cloudy, but that did partially obscure the views.
Now for a word on the camping. I have never liked camping and probably never will. I decided to go on this trip in spite of the camping, rather than because of it, because I wanted to see South Africa and the best trips all require at least some camping. I can say that the camping on this trip was great, almost always more comfortable than the hotels (which isn't intended to be a criticism of the hotels, but rather a compliment to the quality of the campgrounds). The tents are, of course, smomewhat cramped with two people and their luggage inside, but plenty large enough to be comfortable (and a good deal larger than the tents some of the other tour companies were using). The views from the sites were often spectacular (Tsitsikamma and Drakensburg), the facilities fantastic, and the locations convenient. The one exception was the one in Mozambique, which was comfortable and pleasant, but had other issues (see below).
My one disappointment on the trip was Mozambique. The whole excursion up there felt like an inconvenient detour, requiring way too many hours of backtracking over the same roads. The trip notes refer to experiencing "vibrant" Maputo and having a chance for a fun night out. On the reverse trip, you're only in vibrant Maputo for about three hours, and a good chunk of that is taken up with waiting for the ferry over to your hotel across the bay; your fun night out is at the hotel restaurant. I have been told that Maputo actually is pretty fantastic, but you're not there long enough to see much of anything other than derelict buildings and trash, or to experience anything other than heat. The campsite where you spend two nights is beautifully located near the water, but it's seven bumpy, twisting, rutted kilometers from the town. My friend and I did get into town for the diving and had a great dinner there, but we were the only ones in our group who were able to have anything more than cursory contact with the place. I think I would have preferred spending more time in other areas on the itinerary and avoiding Mozambique entirely.
All in all, it's a great trip!