First of all, I am not in Special Ed and have no experiance with it. However, I am a writer and a recent college graduate.
I have an AlphaSmart 3000, and have used it for three years. There are only two drawbacks: the small screen and lack of Internet access (which I need for research). However, the latter is not a concern here. The former can be gotten used to.
I used it exclusively to take notes with for three years. The small size can be a problem, but I've written college papers on it. My notes were very organized. I used tab to show the different subtopics withing a given topic (kinda like a A.a. a1 type thing). While I couldn't see the whole screen at once, it didn't bother me that much. The different files can be used for different classes. I actually loved being able to keep up with the teacher's lecture. Plus, I had readable notes for the first time in years (my handwriting is horrendous).
The battery life is incredible. I literally changed them once a year- and it's only 3 AA batteries. It weighs about two pounds, a lifesaver when kids have so many books- and when laptops easily weigh twice that. Furthermore, AlphaSmarts don't get hot like laptops- no risk of accidental burns. They're also extremely durable. One person in the AlphaSmart forum I used to belong to accidently dropped it out of their second story window and it still worked. I've personally just thrown it in my bookbag without worrying about it- and thius dropped it multiple times.
Transferring is simple and easy, either with the USB cord or infared. There are four speeds (slow to fast), and usually aren't many mistakes, if any. You just can't switch to another program during the transfer. It works with both Macs and PCs.
As for typing concerns: there is a typing program available for the AlphaSmart. There are sticky keys available (it's built in and just has to be turned on). The new model has a 6 line screen; the 3000 and below (2000 and Pro) have a 4 line. Another bonus: no software to update or viruses to worry about. It's very maintainence free.
I'm not sure what else you're looking for, but I highly enjoy my AS3000. I don't plan on getting a laptop anytime soon.