We found Oceania 4 years ago and it is our favourite cruise line by far, out of about 30 cruises in total we have sailed on four of their ships, including the Marina last year. I wrote a review about that trip Marina Review saying how wonderful it was but that gangway accessibility for my husband, who is disabled following a stroke and uses a small folding mobility scooter, would prevent us from cruising on Marina again. Shortly before the launch of Riviera I emailed Oceania to ask whether it had been improved for the new ship and received a polite and apologetic reply that no, it was the same. But then we saw a bargain and the temptation to try the new ship was too much for us, so we booked, prepared to stay onboard in some of the ports if getting ashore was just too difficult. Then we arrived in Athens and were overjoyed to see a (reasonably) accessible gangway ! As with Marina, the main access is up a flight of external stairs to deck 5 but the crew gangway leads to deck 4, and this time there was absolutely no question as to whether we could use it - "of course, madame". In some ports there were a couple of steps at each end and at others it was sloped up and down - rarely possible to drive the scooter off and would be difficult for anyone with a large scooter or electric wheelchair but much much easier for someone like him who can walk a short distance. Also the lift down to the tender embarkation, which had been out of order on Marina, was working and made it much easier too. So well done Oceania for vastly improved, if not yet quite perfect, accessibility.
The next delight was that our inside guarantee, for which a cabin number had not been assigned before boarding, turned out to be a balcony. It was lovely to have and I really appreciated it but it did reinforce our view that we would never pay for a balcony - we only used it for a few minutes each morning to check the weather. Husband said he preferred the wheelchair accessible inside we had on Marina last year, indeed it was much bigger and better for us, but we knew when we booked that no accessible cabins were available (we can manage fine in a standard cabin anyway) and the balcony was a lovely surprise. The bathroom was large and contained not one, not two but three showers - one over the bath and then within a separate small shower cubicle both a handheld showerhead that clipped into a normal rack and a ceiling mounted showerhead, that produced a waterfall-like effect. The bed was wonderfully comfortable, as usual, and we slept very well.
Everything else was almost identical to Marina and just as good. The entertainment, as expected on Oceania, was fine, if not exceptional, the Andrew Lloyd Webber show especially good, and all the singers had good voices and also mingled with guests around the ship and were very pleasant and friendly.
Great cabin, close to aft elevator. Reasonable size bathroom has both a bathtub and an (small) separate shower cubicle.