Karen, for me, it is worth it for the private balcony, as it is my "smoking area" since I don't like to make the cabin smell. I also enjoy sunning, reading, and just spending time on the balcony in a lounge chair at all different times of the day! Like a.m. coffee, afternoon sunning and reading, late night, just sitting out there enjoying the quiet seas going by. Not sure the difference in price. If is a deal breaker, I would probably go with the communal thing, but not otherwise.
Don, I am eager to hear your take on the Cloud. Somehow, I have the perception that the cabins are somewhat the same as the Diamond of yore. Fine with me, I sailed that ship 3 times and loved every cruise.