Are there benefits to using the same cruising company?

Question

My husband and I went on a Carnival Cruise to the Bahamas last year and it was okay. We weren't very impressed but the price was good. It seemed the entire time like they were trying to pretend everything was nicer than it really was...

We would like to go an Alaska cruise this summer. We weren't sure if we should try Carnival again - I heard there are benefits to using the same company more than once - or try a different company. Are they all generally the same? We're looking for something for young married couples. Not the party scene, but also not the family or retired scene either.

Any recommendations?