Welcome to cruise-chat.
I like suites over standard cabins. The extra room is preferable to me, but maybe not so to others. It really is a personal choice. A cat 12 has 345 square feet, a cat 11 has 275 square feet, and a standard inside cabin 185 square feet. That is a lot of variance as far as room to move around, not that the inside cabin's on Carnival are cramped - they are usually the largest you can find on any line. And don't forget the suites have a small refrigerator and balconies. I really like a balcony too.
So to answer your question, yes there is a difference in comfort especially when there is more than two people in the cabin. But it is just 5 nights, and the inside can be tolerated for that long, even by me!
One more thing - most people don't spend a lot of time in the cabin.