For our first trip as a family, we stayed at the Poly, thinking that it would be a long time before we came back (haha!)! We LOVED it, and hated to try any place else. However, we decided to try SOG (DH is active duty Air Force) when we took a trip with our best friends (also AF). The price truly can't be beat, and that it why we are staying there again in May. While I would LOVE to stay at the Polynesian again, I just can't justify the price difference. We are paying $129/night for a ground floor pool side at SOG, and we would be paying $399/night + tax for a garden view at the Poly. By staying at SOG we have been able to extend our stay and are now staying for 12 nights.
For us, the dining plan just isn't worth it. We have 2 small children who usually share meals, and DH and I aren't big eaters either, so the
DDP has never been a deal breaker for us. We get annual passes and the Disney Dining Experience card, and save on meals that way.
If you do decided to go ahead and stay at the polynesian, be sure to compare ticket prices. You can still buy your tickets at SOG (if you aren't on a package through Disney), and you will save some money there. We will be saving $131.60 by purchasing our annual passes at SOG! The prices are just slighty lower, but you don't pay tax.
Good luck on your decision, and know that you'll have fun no matter shere you stay!