Having stayed at both within the last 11 month I definitely recommend the GF! The Poly is nice but the rooms felt old. Se my review for more info. The GF was really great and has a more romantic atmosphere and restaurants. If you want to enjoy some of the Poly's amenities it's a quick 5 minute walk.
This was my recent review (wall of text):
We're Disney fanatics. We fly from home to go to WDW 2-4 times a year and have annual passes. We usually stay at the Grand Floridian or Yacht/Beach club or Port Orleans French Quarter and have come to expect great service from Disney no matter where we stay. We stayed at the Yacht Club during New Years and the Grand Floridian during the summer and both stays exceeded our expectations. We had high hopes when we booked our stay at the Polynesian in a Garden view room. Our last stay here was years ago before all the vacation club remodeling and we stayed until the Tokelau building which had beautiful big rooms but now has been converted to a vacation club property. My biggest complaint with the trip overall was the level of service provided by the resort or rather the lack there of. We did the online check in days prior to our arrival. Our flight wouldn't get in until around 10 at night so I wanted to be able to go to our room directly and Disney is supposed to text or email your room number to you. 6 pm on our day of arrival and no text or email. So I called the Polynesian and explained the situation, they went to transfer me to someone who could help and I was disconnected, called a second time and spoke to an extremely rude cast member (very strange since most cms are awesome) who told me under no circumstances could she give the room number or have a text or email sent. I explained we probably wouldn't get to the room until midnight and her answer was that I would still have to go to the front desk. I hung up and called back, spoke to someone else and was able to get our room number.
When we arrived we were placed in the Rarotonga building which was a nice location a convenient to get to the Oasis pool, Great Ceremonial House, and bus stop. All good things. I noticed there were no runners on the bed like in the pictures but thought maybe it was just a new style of decor.
At 7am I heard what I thought was a cellphone vibrating but it was actually the mood music they play outside. They start it at 7am and it's LOUD in this building. Not sure why they couldn't turn it on at 8am instead. Also the walls seem pretty thin because you can hear a lot of the noise in the hallways in the morning when people are going to the parks
Our room wasn't made up until after 4:30pm and that was because I called at 4 to ask if our room would be made up that day. Still no runners on the bed and the bed looked like my kids made it up. Wrinkled sheets, pillows sloppily placed on the bed. It sounds strange but at the Yacht Club and Grand Floridian the sheets are made so tight you can bounce quarters off it which is why this stood out. Also we went to sit on the balcony and there were spiderwebs everywhere. Above the doorway and on the chairs and table. I wiped them off, but it's still indicative of the relatively poor service we encountered there. We had breakfast at Ohana where I had made a reservation for 4. The hostess messed up when we checked in and changed the reservation to 5 people 4 adults and 1 child instead of 3 adults and 1 child which caused us to wait for an extra 30 minutes at for our table. Just again it was the lack of attention to details that Disney is so well known for which really disappointed us, especially when paying over $500/night. Finally because the larger rooms have been converted to DVC the rooms that are left are smaller and in the older buildings. They look older with shorter ceilings and smaller rooms.
The good or great things were the ability to take a boat or monorail to the Magic Kingdom, the ability to walk to the Ticket and Transportation Center to take the monorail to Epcot, the beautiful grounds, and the Oasis pool with very reasonably priced cabanas.
As much as I'd like to, I can't recommend the Poly when better options are available especially for less money.