We cruise on both, though we haven't been on Carnival since 2019, and have been on Celebrity twice in the past year. Yet, Venezia is coming to NY and I want to see what she's like.
Best to try them out for yourself! Have not had a bad cruise on any line or ship yet.
Remember, ALL major cruise lines have had cutbacks, and they are evident on every ship. I have lowered my expectations and still enjoy watching the sea go by from a ship balcony.