Hi! We just stayed there last weekend. We took the bus to MK, AK, and EPCOT and would have taken the bus to DTD because it seemed a little far to walk. If you like to walk though it would probably be o.k. Less than 2 miles, maybe only 1.5 miles. The buses run every 30 minutes and they run from DTD from early AM to about 2:45 in the morning when PI closes.
BTW, what a wonderful hotel! The suite was HUGE and clean and the staff was so nice! I'm kind of a snob when it comes to Disney and only want to stay in Disney Resorts, but DH surprised me with this weekend and I can't believe I'm saying it, but it was the the biggest room and one of the nicest hotels I've stayed at in Disney (and I've stayed at nearly all of them over the years). I'm sure the suites at the Contemporary or GF are spectacular but they're $$$ and the DoubleTree is great and not expensive.
Have Fun!