First let me say that my wife and I are not active cruisers, having taken fewer than 8 in our 50 years together. We prefer to plan our own trips and see things on our own. We chose the Baltic cruise on RCI because of the 3 days in St. Petersburg and we didn't want to try Russia on our own. It was a mistake we will not make again. If we ever cruise again, it will not be with RCI.
Embarkation was smooth and painless thanks to the pre-cruise checkin process offered on the RCI website. The food and service on Serenade of the Seas were good. The food in the Windjammer was plentiful but if you dine there every breakfast, lunch and some dinners, it becomes somewhat repetitive and is often quite crowded. All the staff that we came into contact with were very friendly and helpful. The entertainment was acceptable but not exceptional. The ABBA show was very nice, but some of the entertainers in the Centrum were boring. The cabin facilities were nice but somewhat tired, especially the carpet and sofa and the in-room amenities were non-existent. Having said all of this, the cruise would have been enjoyable if not for the way Royal Caribbean operates. Everything is designed to sell, sell, sell. They start trying to upsell you the moment you step on the ship with upgraded meal packages, drink packages, photos, excursions, etc. The price for internet service was especially outrageous. Over $26/day for a single device. Very annoying.
As for the ports of call, it seems that they berth the ship as far away from town as they can to encourage passengers to book their overpriced excursions. They provide very little information on where the ship is berthed or what transportation options there are to reach town. There were no port briefings on things to see so if you don't take their excursions you have little idea of what is available. If you don't want to use RCI's excursions at each stop you must do a little research prior to your trip. Try to find out where the ship will be berthed in each port and what types of public transportation is available. The daily tip sheet provided to the staterooms provided very little information.
The cabin is small but fine for two people. The cabin amenties are non-existent. One small hotel-size hand soap each week and a liquid soap dispenser in the shower. No shampoo or lotion to be found. Nothing in the mini-fridge unless you order it separately. Not even a bottle of water unless you buy their overpriced drink package. Nothing in the stateroom to write with or on. Outrageous internet fee. But it was not all terrible. There was plenty of toilet paper.
Took the public bus into town. Used a free walking tour service in town. Walked around Gamla Stan
Long walk into town but worth it to visit this wonderful medieval village.
Walked into town but didn't find much of interest.
On our own took the long walk into town to attend Medieval Week, an annual festival attended by 100's of people from nearby towns in period costumes. RCI didn't even mention that this festival was being held. Shame on them.
Didn't visit Cherbourg, went to Fredericia instead. Walked the ramparts.
Took the public bus into town. Visited Rosenborg Slot, boat trip through the canals, walked to Nyhavn, Little Mermaid and Kastellet.