That's a hard question for someone else to answer. It really depends on you.
Do you have the budget for it?
Are you accustomed to more cabin space when you cruise?
Carnival's suites are nice and they are also roomy but the amenities are far less than the amenities you receive with suites on other lines. They are also less expensive than suites on other lines. There is no butler, special restaurants, free laundry(?), espresso machine, etc. You do receive priority embarkation and disembarkation and priority tendering.
Regular balcony cabins are a nice size and I doubt two people will feel cramped.
I have stayed in both Cat 11 and Cat 12 suites and I do enjoy the extra room but I have no problem with a regular balcony.
Carnival has reclassified their suites so there are now a number of different suite categories based on location and size.
Think about what fits your needs the most and make your decision.