We have done a side by side, MSC to Carnival Celebration. We stayed on first ship as long as allowed then picked up luggage and out we went, (when checking in on-line earlier of course tried to get the earliest possible embarkation time on the Celebration), put new luggage tags on, walked to Celebration (was doable for us, just watch out for various vehicles moving around, some sidewalk is available), and were able to get checked in and wait in lounge area until boarding started. Worked great. The specialty restaurants that are complimentary for your first visit are, when open at lunch time, complimentary for unlimited visits. At dinnertime you do need to check in on App. Pig Anchor/Heroes Lounge also has a complimentary dinner menu, really enjoyed it, fun place. Someone earlier did suggest Pig Anchor only complimentary first time, that was not true for us. And for Pig Anchor we did not check in on App, just lined up at entrance.