Hugs...Welcome to Cruise-chat! If you want information regarding all things related to cruising, you have come to the right place.
I read through some of the reviews of which you speak and understand why you would ask this question. My advice is to not worry about it and enjoy your trip!
Please understand that for whatever reason, people who perceive that they have had a bad experience tend to write reviews and are more vocal about their experience than those that had a very positive experience. That is why it seems like there are a lot of negative reviews on the Sensation. Of course, I think this is fairly common knowledge, however, I have found that the best way to judge this is by reading reviews of your particular cruise when you get back. I have been amazed by some of the negative things that people said about a particular cruise that I had been on, when my experience was completely different! There are just some people out there that aren't happy with their lives and they seem to think that it is everyone else around them, rather that a problem with them. Now, I am not saying that some of the negative reviews aren't true, I am just saying that you have to take them with a grain of salt. When you read a review, if there are objective observations that are both good and bad, then to me it is much more believable than someone who states that everything about the trip completely sucked. I can't imagine having an experience like that on a Carnival cruise.
For example, folks who complain about having to dine with the same table of people every night simply haven't done their homework. A little research into cruising would go a long way towards avoiding such "boring" conditions. Some complained of being rushed through their freestyle dining...and I'll just bet that they were showing up with only thirty minutes left to dine! Anyone claiming that all of their food on a Carnival cruise was "flavorless" and "bland" clearly must have a problem with their taste buds. On all of my cruises, I have only had two dining room main dishes that I can think of that I didn't like and that was simply a matter of personal preference. I still ate them and it was better than eating what I would have made at home, anyway.
The bottom line is that you shouldn't worry about the negative reviews that you have read. Just board the ship with an open mind and I bet you have a whale of a good time.
I am sure that Dwayne or one of the other Carnival experts can be more specific regarding the Sensation.
Have a great time!