Generally speaking the tour is OK.
Well organized, nice inteligent guides, good bus etc'.
I do have some reservations:
If you read about the D-day you realize that the information given is very partial (one can argue that people are tired of hearing the explanations all day long, and nothing can be compared to the book but still.)
The museum in Caen gives very partial information regarding the D-day
I wonder if the price is not too high (200$ per person!!, a bus of 76 passengers, 3 people on the crew - they have a good business)
I think you can enjoy Cityrama tour but if you do not hate military history staff, read the book before, than when you pass through the lovely French vilages you will be able do appreciate what happened on the D day in each one and have a better grip of the whole story
Prof U. Kramer