Welcome to Cruise Reviews!
Don't worry about negative reviews. People are more likely to post a negative one than a positive one, and often the people with the negative reviews have an ax to grind over some minor problem that stuck in their craw and they want to get even.
I have not been on the Carnival Legend recently but it is one of my favorite ships. Focus on having a good time and you will be fine. Nothing is going to be 100% perfect.