DS 10 I thought may be HFA, but the doctor told me he is not, but he called it OCD with anxiety and ADHD. I have taken him to WDW several times. We have stayed at POFQ, POR, AKL, ASsports and ASmovies and he stayed at Pop with my parents once. As far as downtime at the resort, the only thing he misses when he is at a value resort is a slide at the pool. He loves the slides and would ride them over and over again. At the value pool, he doesn't have that, so we have to interact with him more..throw a ball or he has dive sticks that he goes to get. We do alright.
The wait time for the bus at POFQ and All star resorts is about the same in my opinion. The ride to the parks depend on which you go to. He really likes All star movies so that is where we stayed the last 2 trips.
DS is really focuses into wait times. If a sign says 10 minute wait, and you don't get on for 30 minutes, he will have a meltdown. He even gets upset when you get on a ride sooner that the sign says. He thinks WDW should either have no sign at all, or update it minute by minute. So, we stated using fast passes for the bigger rides which help a little because when you get there at the time, you don't know what your wait time is.
In 2005, my mom bought him a pal mickey. He played games with it, it tells jokes, sings songs, and it interacts at the parks with what is going on. For example, at Epcot, when you go to the countries around the world it gives facts and things. It really helped him pass the time. We took him everywhere, and we brought him back when we went there in 2006 as well. It was good for him.