You can use points for staying at the Poly but it is quite expensive.
If you are looking to rent from an existing member it isn't a hassle per say as there probably will be a lot of restrictions and cancelation policies. See once these points go into a non DVC resort they are called "reservation points" and can't be used to book a DVC resort. So if you cancel they have to stay those reservation points and be used at a non DVC resort. Not only that but if you cancel the points go into a holding account. Means you have to re-book your vacation for an arrival date of 60 days or less out and you can't book and travel in your last 60 days of your use year. You can travel in the last 60 days of your use year as long as it was booked before the 60 days of your use year.
So it gets kind of complicated.
Points for the Poly during value season on a Sun-Thursday are 36 points a night, whereas you can get a 2bdrm at SSR for 27 a night during the same time frame.
Yes, you can rent points that could be used for a stay at the Poly; however, I wouldn't recommend it. You can most likely find a cash rate cheaper than what it would cost you to rent points to stay there.
The big savings with renting comes when you want to stay at one of the DVC resorts. For instance if you wanted to stay at the Beach Club villas and compare that to the price for $$$ ressies there. You would be looking at a 40% or more in savings.