YAY! A chance to talk about my favorite resort, the Polynesian!!
Seriously, it's WONDERFUL. If you've ever been to Hawaii, you'll be impressed how well they were able to represent it right there in the middle of WDW. If you haven't been to Hawaii, this is a chance to pretend you're there!
The smells, sounds, and ambience there is to die for, they have great restaurants and places to kick back and relax. PLUS you've got the unbeatable monorail access RIGHT THERE in the main building. You'll really enjoy this, and you'll find yourself enjoying the MK even more because it is so convienent.
Also, the ability to get to the Contemporary and Grand Floridian is a HUGE perk in my opinion - it's almost like staying at all three hotels because you can go back and forth so easily and check out the other two resorts, walk around their grounds and (I highly recommend) eat at some of their restaurants.
A couple of recommendations: check out the quiet pool, since sometimes during the afternoon the volcano pool can get super busy. If you like frozen tropical alcoholic drinks, (or even if you prefer non-alcoholic,) go to the Tambu Lounge up by 'Ohana and get a drink served to you in a pineapple. They'll put pretty much any drink you want in there (including Coca Cola :lookaroun which I though was odd,) and it's just one of those little things that makes it seem like a real island vacation. They also have some tasty appetizers up there, it makes for a really relaxing evening.
I love every WDW resort I've ever stayed at but for me, there is absolutely no competing with the Polynesian. I hope you'll feel the same once you've stayed there too!
Happy vacationing! Take good care of the Poly for me since I'll be seeing it a few weeks after you!