Dear Judy, I liked the Baltics more and the Voyager more, as I found it more stimulating.
An island is an island with stores and beaches, and if the weather is iffy, you only have stores. The history of these islands is fairly interesting, so that is great, but I think you get a better experience doing this cruise during June or September, because it is warmer and dry, but not too hot to tour. This gives you many more options and makes the trip more interesting.
As far as the rooms, the farther you are from the front the better. However, I am not a person who minds the vibrations on the Voyager and I feel the 7 level rooms have a musty and "gas-type" odor around the halls and the vibration at this level is very noticible. For $200 more per couple for a 9 balcony over a 7 balcony, I would opt for a mid ship 9 balcony on the Diamond because of the vibrations. 765 has very strong vibrations like you are dragging on the ground. 746 has ceiling vibrations. Folks on my hall are with me now and are giving me this information. We have also had drainage problems on this floor.
BUT..the food and service are superb and, if the itinerary and value are right, the Diamond is an extremely well run ship. I have no other complaints. We have a wonderful Maitre d' named Mika, the cruise directors are great, the Captain is full of joy and everyone tries his/her best to give you the best of times. RSSC should be commended.