My wife and I are a bit younger than the usual crowd on Princess, in our early 40's, with a couple of young children who spend most of their time in the kid's club or in our cabin with us playing games and reading. We like cruising Princess because the kid's program is pretty solid and it gives my wife and I some time to relax.
This was our sixth cruise on Princess; we've previously cruised on the Golden, Sapphire (2x), Crown and Star.
If you've been on a few Princess ships, you'll notice they're all laid out pretty similarly, though each one is a little different. My least favorite ship has been Crown (because of the bad buffet layout and lack of a covered pool) and the Grand Princess is probably my second least favorite layout. Here's why: