I am also a Royal Caribbean sailor usually, but I myself went on Carnival with my 2 best friends in november.
I spent about 6 hours maybe 7 total in the casino playing slots, and about 1 hours at the craps table. on my 5 night cruise, i ended with right at 6000 points. I got a free specialty dining for me and my friends, and a bottle of wine at dinner.
After i got home, about a week later, I logged into my account and checked "my offers" and i was offered free balcony rooms (100 deposit given back to me as OBC) as well as 100 free play in the casino, and Drinks anywhere onboard for myself. Other offers as well, including 1500 OBC for cruises 6 days or longer with drinks anywhere, which, on certain sailings in an interior room with prepaid gratuities, even after paying in full came out to them paying me around 300 dollars to sail.
I settled on a balcony room on the Carnival Jubilee in May. This is a $2700 cruise i'm getting for taxes and port fees.
At the end of the day, i've been getting far more from carnival than Royal ever offered me. I don't know if this will continue, but i had to book this cruise by Dec4. I did. After Dec4 they are already offering more that need to be booked by Jan3. I expect these will come monthly. we'll see.