from what i've heard from my friend (who has both passports) the waits at checkpoints in the west bank are potentially interminable. now he does have both passports so that might be why
Depends so much on the checkpoint, time, method and mood. If you're a white family driving back from Bethlehem to Jerusalem at 8pm with a foreign passport, you'll barely notice it. If you're an Arab looking young male walking through qualandria at 8am with a West Bank ID card, you're screwed.
Gaza is a different ball game, it's always quiet, almost eerie at Erez, but it will still take over an hour to get out from being dropped off. Getting in is a little quicker.
