ChrisM: Sorry your experience had a few glitches. We were on Mariner last February and had none of the same glitches you mentioned. Cococay had improved quite a bit since the last time we were there (several years ago). More beach areas, harder surfaced walkways to get around, more activities. As for the embarkation: we have cruised 13 times from various ports. We have never had more than a 5 minute delay in dropping off our bags. You didn't mention what time you arrived at the port. We like to get there early, usually 2-3 hours prior to when the cruise line says to get there. Perhaps we've just lucked out
Do give RCI another try. Try the Freedom class or the Radiance class for a change. Try an itinerary that includes Labadee. I promise: you won't find Labadee dumpy. It is one of the best private cruise line beaches, and we've been to Princess Cay, and HAL's Half Moon Cay.