My feeling is that while disney resorts are pricely, generally speaking, you do get something in return - so long as you are using what you get. DO keep an eye out for discounts! I don't know that any are out currently, but there likely will be something. One of the biggest 'returns' of staying deluxe is a the amount of time you save. They are often more convenient.
How much you like a resort is what you make of it. For me, the Poly is one of my favorites for eating, but not my personal top choice for where to stay. The theming is great, and being on the monorail loop is great. It's also convenient to be so close to the TTC. The rooms are big. I also think the Poly is one of the more romantic resorts on property! POFQ would be a good second choice for romantic atmosphere.
Where I'm not so fond of Poly is the layout. It's certainly more convenient than the All Stars and SSR, but it's not my favorite. The other small thing that's not my favorite is the brown decor. Lots of folks love it, but I am much happier with white bedding, bright lighting and cheery colors. I also wish Poly has a real hot tub. That said, the pool at Poly is really neat! Though there is no hot tub, the main pool does have and area with jets (as a hot tub, they just aren't hot). The view from the pool is neat. I also think the food offerings inthe food court are good. You are also very clse to GF, which also has lots of great dining.
My suggestion is often to dine near one's home resort. In the case of Poly - you'll get the best of both worlds when you dine at GF or Poly. If you pick POFQ, then consider some dining at DTD.
Simply put, you should not go expecting an upgrade ever, but Poly has been known to sometimes upgrade rooms within the resort.

At POFQ, there are two room catoegories. It's possible you could get upgraded to water view, but I think that's the only potential upgrade. Disney doesn't typically upgrade toa different resort, unless a resort is overbooked. Upgrades are FAR more likely during slower times of year. October is not slow season, but it isn't Christmas either, so likely rooms won't be totally booked. POFQ is one of the smallest resorts on property.
How much you get out of a resort depends how much time you'll be spending there, how much you appreciate a better pool, etc.
If you stay at Poly, then you owe it to yourself to watch Wishes from the Poly beach (or pool) at least one night!

If you pick POFQ, then you owe it to yoruself to do at least one evening ride on the DTD shuttle boat.