The Fountains is much closer to WDW and you don't have to go on I-4 to get there. It's also larger, has snazzier pools, and there are activities on Lake Eve (Canoeing and paddle boats and stuff). And it's a lot noisier
, at least when we go (May). Might not be true when school's out, since Sunshine is right across I-4 from Universal Studios, so I suppose there are more teenagers there in the summer. I did not notice noise
inside either unit; just talking about noise in the common areas. The Fountains is much busier, with more kids running in the "halls" and the like.
At the Fountains, if you want to be in buildings three or four (oldest units but recently refurbished; have a view of Lake Eve), be sure and get the units that sleep 8 ("Deluxe"). The units that sleep six in those two buildings are the smallest on site ("standard"). Buildings 3 and 4 are closest to the indoor/outdoor pool and the club house, which is nice, but it means parking there can be a bit of a pain -- we ended up parking over by building 5 a lot when we were in building 4.
The ones that are just "2 BR" on the Bluegreen reservation site are the most common. They're in buildings 2, 5-8, and possibly 10. They're smaller than Deluxe but larger than Standard. Building 5 also has a view of Lake Eve, or at least most of it does, while 2, 6, 7 and 8 face the pond they call "Lake Opal" -- 2 is just across a little finger of it from Wakoola Springs, so closest to the pool area aside from building 10.
Building ten you're facing either the road (the building is on a hill above it and a fair ways back) or Wakoola Springs, the big pool area. The Presidential units are in building 10, as are the Superior units, both of which are points pricey. Building 10 is also outside the gate so before you get to the guardhouse, if that matters to you.
The Indoor/outdoor pool is heated; Wakoola Springs, the big lobed pool, is not. There's a water play area, which is also zero entry, in one of the lobes of Wakoola Springs, and two big twisty slides in another lobe. Hot tubs (plus jetted tubs in the units), kiddie pool, all that. There are a couple of regular playgrounds, one at the end of building 2 and one in between buildings 7 and 8. There are organized activities every day, parties at the pool and tie-dying t-shirts and stuff, don't remember how extensive they are.
Orlando Sunshine has only two buildings, is not gated (guards do patrol the resort, though), and may not feel as "resortish" because the grounds are basically the rectangle between the buildings and that's it. Pool, hot tub, tennis court with a basketball hoop, tiny lawn, bit of landscaping around the edges. Then again, we actually did more of the activities there than when we were at the Fountains because we were on the bottom floor of Building one, meaning the kids could run out the screen door in the back and they were right there. However that's only true of a very few units; everyone else has to exit their unit on the other side and go around the building to the pool, which is kind of a pain but you're still closer to the pool than you would be in most units at the Fountains. Dead basic pool; no slide, nothin'. Hot tub is great, though, has a little waterfall.
We liked both, but I'd stay at the Fountains if I was going to spend most of my time at WDW.
It's a bigger Resort & has got alot more amenities. It's got 2 pools, one of which is massive! You need to have a good look on Trip Adviser! It's on the end of International Drive that is closer to Disney. But i'm unsure of how long it will take to drive to it.. 15 minutes? Heres a link to Google Maps where i've highlighted the distance between them - 
