Jim is going on a cruise shortly with an aft balcony, it sounds like a fantastic location to me. I've never had a bad cruise on Carnival, well actually not on any line, but Carnival has always been great. I know I'm a broken record, but I always suggest trying the chocolate melting cake at least once, it's so yummy!
With 5 couples on board, y'all will certainly have enough to keep everyone busy and entertained. Have a wonderful cruise!