I recently cruised on Vista, the newest Oceania ship. It’s an aesthetically pleasant ship with decent food and service, but I find there’s no comparison with Regent. To upgrade to a cabin the size of Regent, plus pay for excursions, drinks and tips makes it basically the same in price, plus you’re sharing the ship with more people. Service in the lounges at night, unless you were seated at the bar, was pretty bad. I’ve been on all the Regent ships( except Grandeur) and I would pick any of them over an Oceania cruise