The Poly is my hands down favorite report at Disney. I would NOT buy there.
Since it is all Studios, and a great number of them, I think you will almost always be able to book at 7 months.
Pros of buying Poly:
1. Guaranteed to get it every year at 11 months.
Cons.
1. Steep price to pay for the benefit of the 11 month advantage, which I think most times will not be needed, which basically means you are paying for a privilege you will not need.
2. Only Studios.
3. High MFs on old buildings.
4. I have heard the same thing about the noise. That was the case in the hotel rooms, obviously Disney did not do anything to mitigate the situation.
I think you can basically pick up an SSR contract resale, pay half the price, and most likely not know that the POLY is not your home resort. If you do this, and push comes to shove, and you have trouble getting into the poly, sell it, and buy a poly resale. Your loss will be the commission the agent gets for selling your SSR contract, and you will probably save that by buying Poly cheaper on the resale market in a few years, when there are more contracts out there. It is for this reason, I basically see NO REASON to buy at the poly.
I also agree, about the fixed week. As a week 48, 49 person, if I were to buy the Poly it would be a fixed week for one of those 2. (And I think every year I would be able to cancel and rebook, banking the extra points)