I got to shadow a D3, and I put those hours on AADSAS. IMHO, it's a nice addition, because you get to see what dental schools make you do that nobody does in a real practice; like put dental dams on everybody who walks into the building. I got to see them do their own billing, scheduling, etc, and I talked to a bunch of the other students. Obviously it shouldn't be your only experience, but I thought it was highly beneficial. If somebody on the other end of AADSAS didn't want to count it, I never heard about it.