This is TLDR, sorry!
For a relatively small building, I find GF SL a very difficult CL to figure out room requests/preferences. I'm trying to remember what I did last time but I think I may have not even done room requests and just left it to chance.
We've stayed at SL twice... April 2017 and Sept 2018. April 2017 was third floor in the middle (over the atrium) and Sept 2018 was third floor down one of the halls (second room from the end). Both of my rooms faced the marina. The other side of the building faces the Courtyard Pool.
I don't deny that I found the middle room 'kind of' noisy. You could hear breakfast service being set up in the AM, glass/plates clanking, just general noise. Not crazy loud, but not absolutely quiet either.
The room in Sept at the end of the hall was quiet as a church mouse... perhaps one of the quietest rooms we've ever had in our travels.
If you'll indulge me for a second...I have been wanting to do something like the below for a while and your post gave me a reason to take a first crack at it.
GF folks, please let me know if you see anything off here.
Here's a general lay of the land for the first floor. The floor plan isn't entirely drawn to scale or accurately, but you get the general idea. The only six rooms I'd really not want in the building are the ones around the lounge. There's a wall between the room doors and the lounge - but it's a little too "right there" for me, especially those two right by the elevator - nearly the entire building walks by those rooms all day everyday.
All rooms on the first floor have normal/standard balconies.
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Here's the second floor... all pretty normal here. The rooms in the middle on the second floor have a full balcony but the railing is a full wall. The rooms on the hallways have standard balconies.
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On the third floor, things start to get a bit different. You have the rooms in the middle, which have standard balconies on this floor... plus the first four rooms down each hallway. But then you get into rooms at the end of the hallways that are vaulted ceiling/dormer balcony rooms. Some people may/may not like this style room or balcony. The balcony itself is much smaller than the standard style and you can't really see out if seated.
View attachment 362727
Some of my labeling could be wrong on this floor, but there are only a handful of standard rooms up here. All are vaulted ceiling/dormer balcony rooms.
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So what does all of that mean? Hard to say! If you feel passionately about not getting a dormer balcony, you may want to craft your request around that. If you feel passionately about being down a hall/away from the atrium, that's an option too. You could just stick to your view preference - Courtyard Pool or Marina, if so inclined. Or you could do what I did and just roll the dice.
"Second floor, away from the middle/atrium, Courtyard Pool facing" would generally describe my personal preference if I could pick a room, but that's a pretty narrow request which I kind of don't like doing if I can help it - not always the best recipe for success.
At the end of the day, nothing I've noted above are really major pros/cons, just subtle nuances to the building.
Just one person's opinion, but hope it helps.
(Again, GF folks, if I've mislabeled something let me know, thanks).
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We had one of the rooms without the white picket fence and garden in front, but it did have a lovely balcony instead. So far it's been our favorite room we've ever stayed in on property. And BTW...I think Disney is very calculating when they pixie dust you with these upgrades! We were actually upgraded to the garden cottage from a garden view room at BWI, and now that we've had that room, it's sadly spoiled us for just about anything else!
We liked it even better than the honeymoon room we stayed in at GF in the Main Building.
Thanks in advance for any advice you can offer. 
She is obsessed with It's a Small World and Happily Ever After so you know where we'll be 
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