Sounds like you answered your own question in the end of your post. Unless you are going to spend your entire cruise holed up in your cabin sitting on the balcony, I think you are putting way too much thought into it. First off, if you are planning on sun tanning on your balcony, consider that you are probably not going to get the best sun there. You will have an overhang from the balcony above you and you have a 4 foot high railing with either metal cross members or glass, neither of which is optimal for getting UV rays through.
As far as scenery, its an ocean, you will rarely be close enough to any land to see anything. Unless you are a huge fan of water, this shouldn't even enter into the equation...
Carnival Cruise Lines:
Fantasy 90, Celebration 95, Victory 05, Conquest 05, Spirit 6/06, Freedom 6/08, Holiday 7/08, Victory 6/09, Valor 9/09, Dream 6/10, Splendor 8/10,Conquest 8/11,Magic 11/11,Triumph 4/12,Spirit 7/12,Freedom 11/12, Triumph 2/13 - The fire cruise, Magic 1/14, Freedom x 2 6/14
NCL Dream October 2006, RCCL Mariner OTS June 2007, Celebrity Silhouette 2013