We have just had a junior suite it was very, very nice BUT the balcony is completely open to the elements be they sun or rain and because they have no cover you have no privacy what so ever. I was very disapointed and wouldn't have one again. Hopefully someone will be able to fill you in on the other balcony cabins it seemed that some were partially covered and above fully covered but I am not sure you will get more feed back.
Some of the junior suite cabins DO have cover. We were on deck 9, and it was open, as you would expect a balcony to be. It was overlooked, but only if people craned over the side, which didn't really happen unless we were arriving/leaving port, if you want more cover look at higher decks or look at the illustration on the website, it gives some idea. The mini suites are a lot more spacious, having a decent sitting area and 2 tv's. There's also canapes twice per cruise, a bottle of Champagne in the fridge, belgian chocs, sweets, a flower arrangement and a single flower on arrival. If you can afford it, go for it.