They'll interline, and the preclearance experience is actually smoother than normal US immigration--rather than waiting for your bags to arrive before going through customs, the immigration officer just shows you a photo of your luggage and confirms it's yours.

I don't know how busy immigration will be during the afternoon with other European arrivals around the same time, but on my two morning arrivals from NRT it was pretty quick, especially with Global Entry. I think last time the whole process of reclearing security, using the GE kiosk, and speaking to the immigration officer took five or seven minutes at most. Just be aware that after that is a loooooong walk to the gate AS uses (at least for QX flights), maybe ten minutes. Whatever the ticketed connection time is should be more than enough unless you DE flight is very delayed.