I never had any interest in Q class ships. For some reason they just did not appeal to me. I booked Odyssey last winter just because the date, price, and departure port worked for me. It turned out that I loved the ship. Q class does have some design quirks, I think O class does have better entertainment, but Odyssey provided a bit more relaxing cruise experience which I appreciated. I also think it haa the most functional WJ that I have been in. That is big for me as I'm a big WJ person.
I liked Odyssey so much I'll be back aboard in a month.