I've often said that most reasonably-in-shape people can "fake" a half marathon, but there's no way to "fake" a marathon. It's hard work, and even when everything goes right, it will be an exhausting and difficult experience. Training-wise, there's not a ton of differences between the two, other than extending the schedule another 4-6 weeks to get some longer distances, but the half marathon is a mostly-physical race while the marathon is a mental one. It takes a certain amount of stubbornness and internal motivation that shorter distances don't need; I think that's why I love the distance so much myself, but I recognize it's not for everybody.
In some ways, doing Dopey makes the marathon seem slightly easier in comparison. You already have a good feeling for how much life is left in your legs, and you've been conserving your pace for several days. Then again, your legs are already tired and your mind is shot from the lack of sleep. The soreness helps keep you from going out too fast (a very real problem at the marathon distance), but it also makes it very difficult to recover if you fall behind pace (either your personal goal or the required pace)
After exiting AK the stretch along Osceola Parkway is relatively straight with some slight inclines and IMO the most boring part of the course. It's also the longest straightaway on the course. Although there are a few character/music opportunities, there's also park traffic along the road and you start to experience the temperature warming and there is no cover. I'm not a huge fan of the WWoS part of the course, I like to use the part of the course to the far south (after the softball fields and before the baseball quadplex) as a recharge point. This is just shy of mile 20 and I typically start to decline here. Luckily there is a well placed medical tent where I can get Tylenol and there is water/bananas. Champion Stadium provides a lift to get you out of the WWoS Complex and back out onto Osceola Pky.
I agree that this stretch is the worst. Coming out of DAK there's really nothing to distract your mind, and it's during the part of the race when most people tend to start to fall apart anyway. Having WWOS as the next "highlight" to look forward to really isn't terribly inspiring to get me to push through the tough miles, making it about 9 miles from exiting DAK to the next real point of interest at the Studios.
Given that marathon registration dropped so much this year, I'm (foolishly) hopeful that they'll reconsider bringing back the old course, with the early loop through Epcot. That layout did a better job of spacing points of interest evenly along the course, making it easier to break into manageable chunks, and had the highlights more closely-spaced in the second half where you really need the boost.
This seemed to bother me much less last year during the half at WDW than it does at DLP, because I remained energized by the sheer number of participants, even though the countryside which makes up almost two-thirds of the DLP course is really beautiful to run through.
As great as it is to run though the parks at DLP (and the courses are laid out to give runners a TON of park time), I really love getting out in the countryside. While somewhat plain, it's just so lovely out there! It's spread out enough that you can focus on racing if you want, but also scenic enough to keep your mind occupied with the autumn crops and village. It's tough to describe why I like it so much, but it's part of what makes that race really unique and memorable to me
