Your choice of ships can be broken down into various catagories. I started out many years ago on the Pacific Princess(Original Love Boat). Eventually graduated to the Dawn Princess(Sun Class)& Coral. At first I thought the ships huge but, really grew to enjoy the Sun Class ships.
Then I tried Grand Class. To me Princess does a great job with creating intimate space on huge ships. I have really enjoyed the Star & Diamond. Will be on the Grand next July.
As for the Caribbean Princess I have yet to experience her. Have heard great reviews.
I think that the standards are similar on all Princess ships with regard to service & food & decor.
The crew on the ships rotate, but, some have many contracts on the same ship. Having them remember you time & time again is nice.
Check out the Princess website for cabin sizes.
You will get all sorts of reviews as to what cabin is the best one. I love to have a balcony. Never had had a suite. But, sometimes the cost of a balcony can get me another cruise so I go to a lower cabin.
For your special anniversary cruise I would go for the balcony for sure. Check out the suite prices.
Hope this helps some