We were unable to book our reservations for dinner months before we left. When we addressed the issue once onboard we found out it was due to Dynamic Dining. We were "invited" to come to the dining room to book our reservation for dinner every night. yay (sarcasm). The line to do this was very long. One of the things we liked about cruising was that everything was "planned". The last thing we wanted to do daily was figure out dinner plans for each night. On the positive, kudos to the dining manager who allowed us to book 2 nights out at a time.
Also, we took our married daughter and her husband with us. Somehow their reservation was un-linked with ours even though they were linked previously. It took quite some time to link the accounts at check-in (and 2 employees to do it). What we found that first night was not only had we become un-linked but ALL of their show reservations disappeared. So we had to go to another line and re-book EVERYTHING. Some of the entertainment they had to go on stand by because Oasis venues could not accommodate them now.
There was very little poolside service. I heard another passenger complaining to the one random employee who was picking up towels about this as well.
Everything from dropping off baggage to boarding would have been great but our reservations became unlinked with our adult children so we had to spend quite a bit of time with IT to correct it.