Hello, first - I have NOT travelled on any of these ships yet, and have only made my own assumptions based on the info I have glenaed from scrutinising the hard copy brochures, the deck plans online and the galleries of people's photos who had been on the Diamond Princess or Sapphire Princess as it is a similar ship. From what I can tell, the decks and balconies are tiered to give better views, but it means that you can look up or down from your own balcony into those all around you - up and down. Also, people up on the bow observation deck can see down into most of the front half of the boat's balconies.
Mind you, almost all reviews on these forums and all others I have read, no one seems to mind, so please don't go on just my opinion. I think all rooms with a bacony are going to be brilliant, and you will love it. I just get burnt easily so wanted some protection from the sun, and my other half likes complete distance from people when he wants quiet time, hence why we wanted as private a balcony as possible. You also have to remember, you may have a 'less' private balcony, but you will have a bigger suite/room since you have booked a better class of mini-suite! AC minisuites have more square footage than AD, and so on up the line, so it is a trade off. And from what I can read, how much time will you really spend out on your balcony?
Again, remember, I have never been on a cruise - ANY cruise, so I am not at all an expert. I am confident that you will love any room you have booked and who knows? They often seem to overbook these rooms so you may end up with a free upgrade to a full suite or something. Don't stress and just look forward to it OK? Happy cruising!