Last year I booked an A3 Concierge GTY cabin on Riviera and had zero complaints. This year I booked a B4 GTY on Vista without really considering what I was doing. I know on other lines guarantee means you can end up with a view of the bottom of a lifeboat or a room inside of the engine bay. What's the worst outcome on Oceania? Should I try to re-book? Picking your specific room seems to be a pretty big deal, but this is only my second cruise so I have no idea what criteria I should use.
(NB I'm probably less picky than a lot of people here because I don't know any better, but the best part of my first cruise was reading a book on the veranda and watching the waves so I definitely want to be able to do that.)