We were WDW vets for years, but have moved to AZ, so we're DL AP-holders now. We have 2 sons with cerebral palsy, so we're very familiar with the differences btw the 2 parks.
DL has MANY alternate entrances, and many of the attractions do it differently. Compared to WDW, DL was built much earlier, before ADA. So, while many queue's in WDW allow for regular entrances, DL has many more alternate entrances. Most of the Fantasyland rides enter through the exit; Splash, Space, Indy, and POTC also go through the exit, but usually have alternate accessible lines there, so be sure to look for them. There are usually CM's there to ask, and that's what we did until we got familiar with the procedures...but even then, sometimes different CM's will do it a little different, so just try to be flexible.
Most of the attractions in DCA are much more accessible, and have most GAC users to enter through the nl queue.
Hope this helps!
W