Princess versus Celebrity?

Princess versus Celebrity, What are the pros and cons, which would you recommend? I am a young male age 32 . I am planning to go on my first cruise vacation with my newly wedded wife.
We do not have any kids and have been to some all-inclusive resorts. I have heard about so many cruise lines and seem to be leaning towards Princess or Celebrity. Can you help me with our final choice?

Princess or Celebrity Which one do I prefer?

For me personally only thing I noticed is that Celebrity's passengers tend to be older than Princess’. We are in our late 40s and always end up to be the youngest on the Celebrity ships, where on Princess we were the average and always made tons of new friends.

I also like the option of Anytime Dining on Princess as an option. Also, I believe, that Celebrity's itineraries include more sea days, so if your interests are in the itinerary and not having more days at sea, you may pay more attention to Princess.