This was our fifth Carnival cruise and the first aboard the "big" Conquest-class ships. Overall, it was a fun time. I'll hit the high points here.
Buffet - Many reviewers have commented how the buffet is difficult to navigate and very crowded. We also found this to be the case. There are four "main lines" which include both salads and entrees - unlike other ships where the salad is separate. This did cause lots of bottlenecking. There was a separate dessert bar, grill, pizza, and fish and chips counter. There are lots of seats - always managed to find one.
Internet Cafe - The ONLY way to access the Internet cafe is walking through the very large Cigar Bar - it has no other entrance. If you are sensitive to smoke (especially cigar smoke) - you may want to bring your own laptop to avoid having to do this. It's also quite small (for such a big ship) - only 10 stations. Internet quality was hit or miss - sometimes OK, sometimes very slow.
Smoking - Other than the cigar bar, I didn't notice people smoking much at all (a few in the casino, but not many). This was the least "smoky" cruise I have been on - and I think it is because there aren't that many smoking areas any more.
Embarkation - we got there a little later than normal (around 12:15) but still got on within about 40 minutes. I was traveling as a single parent so I had the form my wife signed allowing me to take the kids out of the US - no one ever asked for it (but if I didn't have it, they probably would have).
Debarkation - pretty easy, we got off around 8:40 and we had our car parked at the pier. If you were willing to carry all your luggage off yourself, they started doing that at 6:30 AM!
Shows - We saw a Beatles Review, a New Orleans song and dance, and a big band (40's) song and dance. We enjoyed all of them. The showroom is huge and we never saw it completely fill up.
Cabin - Standard balcony cabin on Deck 7. Never heard any noise except for people talking loudly in the corridor. Nothing from decks above or below or adjacent cabins.
Dining Room - We had a great experience here with Katarina and Richard. Good food every night. We did not do the Steakhouse on this cruise, and given the intensity which they were pushing it, I imagine that you could have gotten in if you wanted to. They also advertised their "Chef's Table" (which has been discussed extensively on the Carnival Forum in the message boards) - we didn't do it but it is available.