We have taken three cruises since the resumption - two on Carnival and one on Celebrity. Vastly different experiences between them, but all excellent. In general, we felt safer onboard than we would have eating out in Florida. I still tested before work for two weeks after each cruise, because I work with a particularly fragile population. The new muster process is fantastic, I'm a big fan of the improved app offerings, and we of course loved having fewer passengers aboard.
In particular, we were overwhelmingly impressed with Carnival's new ship, the Mardi Gras. So many food and beverage offerings, the neighborhood theming was well implemented to break up the enormity of the ship, and the staff was superb.
We're holding off on booking more until we have a little more data on Omicron. My work keeps me pretty cautious, even though we are personally very low risk. Carnival kindly offered us some absolutely spectacular casino deals in exchange for a couple hundred bucks lost apeice, so hopefully we hear that 'boosted' individuals have a suitably low chance of transmission soon.