There's no reason to not download the new app, because it doesnt' replace the old one. You can still use the old app if the new is installed.
For me, the new app is just a design makeover of the old app. Same makers, definitely. And it's even less functional.
Much more loading time - just like at the beginning of the old app. lol. Back to the roots?
I still can't chose a future cruise like in the old app. It only shows me the next one. Well done, folks. Not. 😞