We all have different likes and dislikes, so it is hard to give advise on which optional tours to choose. We took this cruise last September when the weather was generally cool, overcast and damp, but enjoyed the trip nevertheless. As a rule we usually take most of the optional tours. We skipped the Delta Works and Marksburg Castle this year as we had done them on previous trips. Personally, I did not find the Delta Works that interesting, but it is an engineering feat, and some of the men were fascinated. We really enjoyed the Marksburg Castle optional on Great Rivers cruise, so we stayed in Boppard this time and took the Sesselbahn chairlift to the top of a mountain where we had a beautiful view of the Rhine. However, to enjoy Marksburg Castle you do have to walk up some steep steps and cross some uneven ground at the entry. The Alsatian Highlights Tour was also enjoyable. Stork Park is not a "kiddie park" as a previous reviewer wrote, but a conservation center devoted to reintroducing the storks to the Alsatian countryside. Requiwihr is a cute, picturesque, although touristy, village in the wine countryside. If you like Rococo Architecture, you will enjoy Augustusburg Palace. After the palace tour there is time to tour the gardens which should be lovely in the summer - the flowers were limited in late September, but it was still pleasant to walk the grounds. We took the optional Luxembourg Tour as did most travelers. You spend the morning at the Battle of the Bulge Cemetery which is very moving. Then you have lunch in Luxembourg, followed by a walking tour. That left us with only a short time to explore the beautiful historic areas. I'm glad we went, just needed more time. Personally, I would rearrange the optional: start in Luxembourg with the walking tour, followed by free time and lunch on your own, and then visit the cemetery on the way back to the ship in the late afternoon. It almost sounds like you are planning to do Luxembourg on your own. If so, it was about an hour bus ride from Zell where the ship was docked. The Liberation Museum optional was not offered on our departure, as the ship had to dock in Tiel, instead of Nijmegen. Which optionals to skip? It's up to you. I tend to go on most because I don't want to miss anything, and I enjoy them all. Some are just better than others. Have a nice trip.