I had cruised on the MSC Divina two years ago, and really enjoyed the ship. MSC was promoting a "matching status" program, plus "drinks on us" for those sailing to the Caribbean, so I decided since I enjoyed my time on the Divina, this was a good time to sail on the Seaside.
I have sailed with RCCL, NCL, Disney, Celebrity, Holland America, Princess. Though I thought the Seaside was a beautiful ship, and many of the staff were excellent, I still did not feel "at home" on MSC. There were not many activities for people in my age group, over 65. The shows were excellent, but after awhile began to feel the same after seven nights. The food was good, no issues. A very friendly captain, although I have forgotten his name at the moment.
I had an inside cabin, very small, but found the storage to be fine. The ship can be very, very crowded, on sea days there were no lounge chairs to be found, and the buffet always seemed to have so many people, that I decided to have breakfast in the dining room, it was quiet and relaxing. I have sailed on larger ships before, never experienced crowds like I did on this ship. Also the deck plans can be confusing, you sometimes have to go up or down one deck to get to where you want to go.
Small but not bad, found the storage to be fine, although didn't like the closest set up, had to move the sliding doors from one side to the other to get to my clothing and drawers.