DH & I took our first cruise together (my 2nd, DH's 1st) on the Diamond Princess in Sept. 06 to the Mexican Riviera and we had a WONDERFUL time. We wouldn't change a thing about it. Granite, some of the pool games were kind of cheesy but we watched and laughed our tooshies off @ the comedy of it all. We liked the fact that the ship was soo large that you could barely tell there were 2600+ people on the ship. The shows were phenomenal as was the food and service. Everyone we met was so nice. We even met 5 couples who we stay in touch with even to this day. If you go PCL and dining is a concern, take the early seating that way you can do the shows. Again, granite early seating is I think 6 (don't remember exactly) but we were glad b/c we got in quite quickly to see the shows right after dinner. We even played BINGO a time or two. Oh and did I mention I entered a Karoke contest.

DH and I are coming up on our 5th anniversary and considering taking a Hawaiian cruise this time and we'll definitely be going with PCL. The entertainment staff was great too. They kept us entertained. We really enjoyed the ADULT only pool toward the front of the ship although ½ the time you didn’t even realize there were children on board b/c most of the time the pools were deserted. The best time we had by the pool late in the evening we went to the pool in the back of the ship, NOONE was around and we had the pool and the hot tubs all to ourselves.
Oh and I HIGHLY recommend snorkeling in CABO (if you are going there).
As for the shore excursions, we did some snorkeling in Cabo San Lucas. Mazatlan we got a taxi and he took us around the island, we carpooled with 4 young ladies in a caravan on our own (didn’t take the PCL tour) and we felt really safe. We even got a tour of a tequila factory. In Puerto Vallarta we took one of the tours PCL offered, it was OK but the driver dropped us off right in the middle of “tourist town� where we were hounded by all the vendors to buy their stuff. That’s one thing that irritated us the most.

Of course I fault that in no way on Princess. And then when we got back to the resort to have lunch, vendors were down @ the beach but couldn’t come up to the wall of the resort, but once you made your way down toward the beach to go swimming, they swarmed like flies on poop.
HOLY CRAP, I could go on and on about our trip but I won’t bore you.
OH AND MOST IMPORTANTLY, look at your bar tabs before you sign the receipt. DH didn’t and we were charged a time or two more than what was supposed to be charged. So look at ALL receipts no matter what.
As a poster above said, take it for what it is. A cruise is all in what you make of it, you focus on the negative, you get nothing but negative, you focus on the positive, you get positive.
Anyway, have a wonderful trip and focus on the positives, not the negatives and make the best of your vacation. I’ve been on carnival but that was a long time ago and I was younger (early 20’s) and it was fun. Anyway, have fun and keep doing research.
Now I've only been on 2 cruises and by far I felt that Princess was great. JMO though.
Good luck and have fun, fun, fun!!!!