We just returned from this cruise (May 10th) aboard the Dream. The ship is very nice and the area was absolutely beautiful.
One major turn off was the fact that smoking is allowed almost everywhere on board. We were not prepared for that and, since we don't smoke, it ran us out of certain common areas. At times it was too cool and windy to be outside but you should have a bit warmer weather if the smoke bothers you.
There are several places to dine. All the food we ate was very good. The Four Seasons is very nice as is Le Bistro (cover charge for that one). They and the Terrace all provided more formal atmosphere. We are in our 50s and were among the younger set on board. We noticed most people liked to dress for dinner. We preferred not to and so chose the restaurants we ate in.The Sports Bar, on Deck 12, offers coffee and tea 24/7 and buffet style meals along with a great view from the AFT section of the ship. When you approach Sweden it is worth getting up very early to see the archapelagos from Deck 12. You will be crusing near the time of the Midnight Sun and that is breathtaking at 4 a.m.!!!
Our cruise had appx. 1,660 passengers, so it was not fully booked. We had an outside stateroom with 2 portholes and it worked fine for us.
Finally, read the tour information carefully. We learn each time we travel and wish we had taken more 1/2 tours such as city highlights, etc. Some of the full day tours don't allow any time for shopping.
Hope you have a wonderful time. We met lots of nice people from all over (a big bonus of freestyle dining). We were so taken with Stockholm, Copenhagen and Oslo we would make another trip there in a minute. Russia was fascinating. Finland is a bit rural but that might be perfect for you. Each to there own.