Once Aaron was asleep for the night we were good to go. He would let us know when he needed fed, but he would quickly eat and fall back to sleep. It was very efficient and non-disruptive. Abby takes a long time to feed in the night and then she takes a long time to wind back down and she doesn't do it all that sweetly.
Abby doesn't spit up much. Aaron spit up a lot more.