We will be in the BWV's in Sept. We opted for the 2 BR Villa with "Boardwalk" View, it is not called a water view on the DVC website, the BW Inn may call it something different.
In my opinion, and I may be looking at it a little naively, we spent 25 or so extra DVC points for the Boardwalk view, it didn't cost me any actual money. We had the extra points due to banking most of last years points, and we though we would splurge I guess. If I were paying cash for the room, and it was $800 more for the view, $100 per night, I highly doubt that we would have done it.
We will be staying at the BWV for the first time, and it is hard not to think that the boardwalk views will be anything short of amazing. We are thrilled. Plus, we will be there with my in-laws, who will spend a lot of time on the balcony's and in the room, as they can not spend as much time in the parks as they used to. We will also have an 18 month old with us who will not be able to do rope drops and EMH all day every day. We will inevitably have nap times and fussiness to contend with. All of this will result in a little more time spent in the room than usual I am sure.
I personally think that it will be well worth it, for both us and them. But, I do understand, with all of that said, it is not costing us any more money per say, just about two days worth of DVC points for a suite room in the future, depending on resort.
We had the same decision to make when booking our trip, and opted to go with the boardwalk or water view. I do tend to agree with the others that I will ultimately come down to how much time you plan on actually spending in the room.