You could poll 100 people who have stayed at the GF or Poly and I'm willing to bet that the split would be close to 50/50 on those having good experiences versus those with negative comments. And for whatever reason, whenever you do think you've decided on a resort, up pops a bunch of bad reviews.
The GF is one of our favorite resorts and we've had mostly good experiences there. I choose it because personally, I love the theme. The Poly really doesn't appeal to me at all, but that's what makes a Disney vacation so great. All those choices and price ranges to fit your personality and your priorities for this particular vacation.
While it's nice to hear about everyones experience, the bottom line is that it's their experience. I'm not saying that negative remarks aren't appropriate, just that perhaps something that bothered someone else would not be a big deal to you, or a situation that rolled off our backs, might have bothered you more. My suggestion is to read up on the amenities offered by both resorts, search out pictures (some great ones on Allearsnet.com and Ourlaughingplace.com) and make your decision based on whats best for your family and this particular trip.
Tammi