AMA Europe River Cruise- Captivating the Rhine

Traveling on this cruise next May with my 90 yr old father-in-law and 80-year old mother-in-law. We booked the pre-cruise package in Amsterdam and wondered if it is worth the money to do the post-cruise option in Switzerland. Would like to know your experiences if you've done this. The more I can prepare them...the better! Amazingly and thankfully, they are both in relatively good health and active.