We've stayed at both, love both but on balance the Polynesian is our favorite.
I love the Victorian flavor of the GF but don't find the Polynesian dated in any way. Actually, the Victorian age was quite a way back now!
Agree with Texowl2's points about the TTC and parking. Staying at the Polynesian, we sometimes walk to the TTC and pop over to Epcot just for dinner. If you are taking the buses from a park, you can also hop whichever comes first...the TTC or the Polynesian bus.
The GF has some great restaurants but Kona while more informal has truly wonderful food. At any case, all monorail restaurants are just a ride away from both resorts.
Wishes is incredible from the Polynesian. Well, actually my daughter and husband also saw it this trip from Narcoossee's and said it was wonderful from there too. I do think you have the most "centered" view from the Polynesian.
There are some very friendly CMs at the Polynesian many of whom have been there for years.
Two great resorts...have fun whichever you decide!
Oh, BTW unless it has changed you can still request turndown at the Polynesian for any room. Years ago it was automatic throughout the resort.