I hate to disappoint you, but it's really better to be disappointed now rather than when you get to the ship.
>> If the brochure lists a cabin as "obstructed view," it's usually totally obstructed or very nearly so. Nonetheless, you will get some daylight into your cabin.
>> If the brochure lists a cabin as "partly obstructed view," you probably will be able to see some of the passing scenery.
Aboard MV Grand Princess, the Emerald Deck is a great location. Since that deck has only cabins, it should be pretty quiet.
I have to agree with "juliejoe" htat your chances for a further upgrade probably are slim.