I did the Panama Canal onboard the Joy in January of 2023. I did a shore excursion that went from the Pacific through the old locks to Gatun Lake. Then the next day we took the Joy through the new locks all the way from Pacific to Atlantic. It was one of my favorite cruises. In fact, I booked a cruise January of 2026 on the Bliss going through the other direction. So if I do a shore excursion from the Atlantic through the old locks to Gatun Lake, I can say I've been all the way through 3 times in 2 cruises! In the picture, my excursion is in the old locks and the cargo ship is in the new locks.
For the Joy's journey through the locks, I stayed in my balcony cabin and had the View from the Bridge on my TV turned up. I went between the two to watch everything. Being under 5 ft., I knew I wouldn't see anything from the bow anyway, LOL. I'm not on a balcony next time (at least not at this point; we'll see if prices go down), so maybe I'll end up venturing out to the bow.
As an introvert solo cruiser, I'm a fan of Norwegian but Princess' itinerary is very similar. The cruise from Cabo, Puerta Vallarta and Acapulco is amazing if you are a fan of marine life. I saw whales breaching from my balcony and sea turtles eating in the port where we were berthed. I missed the dolphins, but there was a pod of them that went by as well.