Our last trip in March, I had reservations directly through the DH but about a week before, Expedia was able to beat their nightly price for a view room and included a gift card for $150! I switched out my reservation right then and there and then called the hotel to have our "requests" switched to our new reservation. I was afraid that we would get the "bottom of the barrel room by booking with expedia but the CM assure me that was not true. Everything worked out great and we even got upgraded to a suite for the first time ever!
The catch with expedia is that you generally have to pay upfront at the time of booking, not always, but a lot of times. I have also booked with them and cancelled and they charge a fee of $20-$25.
I have used them a lot of time for everything from hotels to air for Hawaii and have never been unhappy. The rate for PP of $165 is almost always on expedia for months out but as the time gets closer, generally the rate gets higher and higher and the days available disappear. You can book it and watch the rates, sometimes I have paid the cancellation fee because I have found it cheaper somewhere else. Since the time you are planning for is so far out, I might be tempted to wait a bit and see if there are any promos released like stay 3 nights, get one free or stay 4 nights, get the gift card!
By the way, we ended up at DL a day early and had to stay at PP that first night since DH was sold out. We had a view room on the upper floor and loved it! The view was so so cool and so worth the few dollars more. I actually called down in the morning asking to stay and that is when we found out we were in a suite at the DH! I think in some ways, PP is nicer than the DH but my kids love the DH pool so we always stay there if we can.