Just returned from the Baltic Capitals cruse on the NCL Star. We booked this cruise for the cities it visited, not necessarily for the ship or cruise amenities. We are a couple in our 40's, traveling on this cruise without our kids, and wanted to maximize the amount of time and the experience we had in each port.
I think if I were taking a cruise to enjoy the at-sea experience I would pick a different ship and probably a different company. I viewed the Star as a floating hotel that got us comfortably from port to port. We did enjoy some of the restaurants and managed to make it to 3 of the shows, but didn't participate in any of the other ship activities such as art auctions, spa treatments, fitness seminars, jewelry sales, etc. I would have appreciated/expected more information about the ports we were going to that wasn't focussed on getting you to book an excursion through NCL. We did go to a Russian Language class the day before our St Petersburg stop and that was helpful, but I would have liked to have seen several more educational presentations that were complimentary.
We were in a balcony cabin, 10688, that was just fine for 2 adults. Having the balcony allowed us to spend more time in our room, especially enjoying the scenery as we sailed through the Swedish Archipelago, which was lovely. Our steward, Jose, was very attentive and friendly.