My wife chose this tour, and of all the things we had planned in Krakow, this was the one I was least interested in. I was pleasantly surprised how enjoyable it was, and even more surprised at how beautiful the scenery was. Poland really is beautiful! You visit three castles and spend some time in a national forest. I certainly recommend this tour, but here are the things you should know before you go:
There is a good amount of walking so wear comfortable shoes. If you have trouble getting around, being on your feet for long periods of time, or navigating stairs this might not be the tour for you.
It will take you most of the day. The tour operates at your pace, but to appreciate everything you should take your time and soak everything in. You do stop at a nice, reasonably priced, Polish restaurant for lunch, but that cost is not included in the tour. If you're looking to save time or money, I assume you could pack a lunch and skip this part if you'd like. Our guide was extremely flexible with things like that. He will also stop at restrooms and shops to purchase things like coffee or snacks along the way if need be.
Lastly, the tour guide does not go into the castles with you. He will drive you to all the places and obtain any necessary passes for you, but he will wait for you back at the car while you tour the castle/sites. Personally, my wife and I really appreciated this aspect of the tour. It allowed us to go at our own pace, take extra time to look at the things we found interesting, and just kind of breeze past the things we weren't as interested in.
As I said earlier, I was definitely surprised at how much I enjoyed this trip and would recommend this tour highly. It certainly went down as one of the highlights of our trip to Poland.