Recently I had the opportunity to speak with a Princess Cruise Planner Michael, he was outstanding in helping us line up our first cruise on the Star Princess to Hawaii in 2/24/2021 out of LA. After our last cruise on the Vista I was disappointed with the ship and its stops during the Western Caribbean. We have on cruise left on Carnival and on to Princess.
May I ask what your disappointments were with Vista?
Vista layout terrible, had to traverse the smokey casino to get anywhere. I like to play craps and would not due to the excessive smoke. Did not like the stops for the W, Caribbean (two trapped ports) just a tourist stop. Food and Staff great.
In order to see the real difference in cruise lines, you need to do similar itineraries. Comparing the Caribbean Islands with Hawaii is not really a fair comparison. That said, I like sailing on Princess and didn't much care for the Vista either. My big gripe with the Vista was the auditorium seating. The seating was just chairs like in a high school auditorium and people moved them to suit their needs, which might leave you with your knees up around your ears if the person in front of you wanted more leg room. There was no place to set a drink (except on the floor). I don't know if the problem has been fixed or if the Horizon and Panorama have the same configuration. My solution: sail on other ships.
Sorry you didn't enjoy your cruise and I hope you find Princess to your liking.