It depends. If there are little ones, then I would choose 2 BC/3 BLT just for the easy walk to MK.
If this is older children or adults only, then I would go with 3 BC/3 GF because of the pools, the dining options and the view. Poly std. view is okay but nothing special and the volcano pool can get very crowded.
Two adults: I voted for three nights BC and three nights BLT.
Sounds like a great split! I would rather have a Theme Park view at BLT than staying at the GF. DH does not like the crowds at MK for fireworks, so that would be a win-win for us.
I would look into BLT Lakeview too. We prefer that view (it's much prettier during the day IMO) and you can just walk down to the bridge to see the fireworks. And you can save a nice bit of money