Just be aware that the Solutions At Sea that you must use (you can not use your own TA or PVP) is owned by ICE. (the same folks that owned the CVC)
We have had a Carnival Rewards card since they came out years ago....so my opinion is jaded because the first card the fantastic....and sadly they have gotten worse and worse with every change.
We finally used the last of the Sea Miles and threw the card away.
50,000 points is suppose to get you $500.00 off your cruise. Well..not exactly. We got $375.00 off for 50,000 points because we had already gotten the Past Cruisers Discount.
That is the main complaint I have heard.
We are currently trying the American Express Blue Sky card which gives you $100.00 for 7,500 points off airline tickets, cruises, car rental or hotels. No annual fee. You can use whomever you want to book it. It is basically off your best deal. I don't know the interest rates because we always pay our card in full every month. Plus they gave me 30,000 points to join. We will see.