Hi there! I have lurked on this page for awhile in planning my trip and just got back from 5 days at the Polynesian and thought I would share my experience since I enjoyed reading others' trip reports and advice!
My 4 year old son and I went with my parents and stayed in 1 room (standard gardne view). We were originally assigned to second floor Rarotonga but I had requested balcony or patio on the online check in. I asked for a switch before even going to the original room and we were assigned to Fiji 3310 instead, except we had to wait for it to be ready for about an hour. I was very glad we waited. This room faced the Luau Cove with a partial water view and beach view and we enjoyed using the balcony.
Room: You could definitely hear noise from Luau Cove- it wasn't enough to wake my son up but it was enough to be a little annoying. The beds were super comfy and overall it was spacious. The fold out bed was perfect for my son- it was way better than sharing the other double bed with him. The building had one tiny elevator but we never waited for it and it wasn't a problem. It was also a very short walk to everywhere, except the TTC. My biggest complaint is the A/C. There was no way to keep on the background fan even when I changed the fan setting. Even the bathroom fan shuts off if there is not movement. There is an overhead fan which has 3 settings- HURRICANE, barely on, and off. I wish there was some way to have a background fan on for noise.
Construction: Being in the Fiji building I hardly noticed the construction. However if you were in Rarotonga, Samoa, Hawaii, or Niue, or Tokelau on the construction side it would have been awful. Tons of equipment, and noisy, and from what I saw it is nowhere near being done. If you had a child who was trying to nap during the day, or if you were trying to sleep in, I think the construction would make it impossible. That being said, it did not affect MY trip any so I can't complain.
Food: I ate at Kona Cafe the first night. I had the scallops and they were great. My son had the kids Mickey check grilled fish meal and the fish of the day was salmon. It was wonderful. The wait for the food after ordering was fairly long. We also had a breakfast at Ohana with Mickey, Pluto, Lilo, and Stitch. The food was quick, hot, and all pretty good. The orange passion fruit guava juice was my favorite and the characters were great. We ate at Captain Cooks twice and grabbed a pizza there once from the pool. The first time at Captain Cooks for dinner was quick and we had 2 Caesar salads, my son had snacks of oatmeal and applesauce and milk for his meal (hey whatever makes him happy), and I grabbed sushi from Kona Island. The second time was for breakfast and it was a zoo. We waited almost 20 minutes for food but at least it was good. The Tonga toast was great and the breakfast platter was enough to feed 2 adults at least. I thought the dinner/lunch menu had better selections that I expected for a QS resuarant at Disney.
The time I grabbed a pizza from the pool I wished I had gotten the pulled pork nachos instead- I was waiting for my pizza and kept seeing others getting the nachos and they looked amazing. My dad and I also sat at Trader Sam's terrace for a drink once. They have live music and the atmosphere is lovely. We both had margaritas which were pretty boozy. I wanted to order the Tiki Tiki Tiki Tiki Tiki Rum just because I ilke puns but I resisted.

However i did gt some terrible bug bites out there which I never got anywhere else on the property.
Pool: We loved the pool. I love how there was a beautiful view of the lake and Grand Floridian from the area. After reading here about hair in the pool and crowds I was scared but I had nno problem with either. The pool was clean and refreshing. The splash pad kids area was perfect for kids. I tried out the slide in the big pool and it was definitely fun. We spent a whole afternoon here and the activites were also cute for kids. We got there at about 12:30 and had no problem finding shady chairs.
Other: I sat on the beach for 2 different nights to watch the fireworks and it was super crowded. I am guessing a fair amount of people not staying there might eat at Ohana or the Luau and then hang out. There also wasn't any music piped in there (disappointing) or in the pool but supposedly the lobby area and Trader Sam's terrace have the music.
Also, we went to the Magic Kingdom Wednesday and Thursday (Spet 16 and 17) and the crowd level predictors predicted a 2-3/10 and the actual crowd level ended up being a 5-6! Many people we met were saying they come every year at this time and it is never as crowded. I also heard the Halloween parties were insanely mobbed. The crowds ended up not causing any major issues for us but it was disappointing to have longer lines than anticipated. But overall we had a blast, especially my son for his first ever Disney trip!
Let me know if you have any questions and I hope this review is helpful.