If it were me, I would make a list of the pros and cons of each choice, and then go with the one that has the least cons (or at least the most cons you can live with).
You are within walking distance of DTD (although you would be at the farthest hotel) and you are also within walking distance of several restaurants on SR535, if you stay at the Doubletree. You would have transportation, but not as frequent and convenient as Pop transport, and you would have to pay for theme park parking if you drive. You would have more space, the fridge, room for the adults to lounge separately from sleeping kids.
With Pop, you have EMH, frequent and convenient Disney transportation, ability to buy package with dining and tickets, free parking at the theme parks (if you have a car and choose to drive), package delivery to your resort, room charging at the parks, and resort wide recreation access (with the exception of pool hopping).
If the prices are exactly the same (within a few dollars), then I would probably stay on site and save my points for a non-Disney getaway. If you can get the package with dining for nearly the same, then I would definitely stay at Pop. But only you know what will work best for your family (and there's nothing worse than one of the kids sleeping on the floor because they just couldn't share the bed another minute - been there, done that).
I try to get the best of both, and use my HHonors cc at Disney to get points, and then use the points to go other places (I try to do a non-Disney trip every other year or so).
to the DIS!
