This was my third Oceania cruise and my second on Riviera. I think the ship is the perfect size and its amenities fit my priorities very well. The service is really excellent, although I have had some issues with Canyon Ranch Spa's attentiveness not being up to par. The food is quite good and I was surprised to see reviews saying this is not so. I generally stick to the Grand Dining Room and the specialty restaurants and have with rare exception found everything first rate.
While the expected service touch points are generally good (wait staff, cabin service, reception), I m not sure the recovery is quite so expert when something operatinoal goes awry. For instance, we had a problem with our AC on this latest cruise (unfortunately, it was unusually hot, even for the Mediterranean in summer). We had workers traipsing in and out of our cabin for hours, even returning after midnight to retrieve an extension cord after we thought they were gone for the night and had gone to sleep. Due to language constraints, no one was explaining what was happening. Once this was escalated to the Executive Concierge and General Manager, and our travel agent the follow-up improved, but surely they should have a responsible, English-speaking supervisor short of that!
I rarely attend evening entertainment, and don't much care about it, and although there appears to be some attempt to improve it, if this is one of your big cruise priorities, Oceania is not for you. The shore excursions are very expensive -- some itineraries are more overpriced than others, but generally my travel companion and I try to book our own. Oceania does offer some unique tours and at least there is some imagination applied there. (I did note that the mark-ups were not quite as bad in the Carribean, probably due to the heavy competition on those itineraries.) Planning independently can be time consuming, though, and it's worth weighing the value of your time versus the savings you will realize.
These aft cabins with extra-wide verandahs are a great deal. Adds spaciousness.