We used Luau Beach.

But we asked to be as close to the Wedding Pavilion as possible, because that's what I wanted in the background for the ceremony. They put us really near to it!

Our onsite coordinator, Danny, was really sweet. He specifically went down and chose the spot and made sure our little circle of red petals was set up perfectly. He met us at the limo when we got to the Polynesian and took us inside to meet our officiant, Rev. Jack Day. We all rode out to the ceremony spot in a golf cart and our violinist was waiting there for us. It was really lovely and we were so happy with it! We had a 9 a.m. ceremony and the light was really nice. The only small negative I can think of about the site is being near the water, it was pretty windy.
After the ceremony we took more photos, then Danny drove us back to the lobby and we took the limo back to the Grand Floridian for more photos and to do our cake-cutting and toast. Then our photographer left and we went down for a breakfast of Mickey waffles!
Randy put up a few previews for us, and these 2 show where our ceremony was:
I hope this helps a bit -- I'm happy to answer any more questions you think of!