We've taken them out 3 times and this last time we did have some trouble when we came back with the amount of unexpected homework that had to be made up. I had asked the teachers for homework for them to do while we were gone and I felt that we were all on the same page, but when we came back my kindergartener had over an hour's worth of homework that was sent home with him and my second grader was bringing home 6 extra sheets a day for over a week. That's on top of what they were given to do while we were gone, which for my second grader was 20 pages of math, 2 essays, 1 story with comprehension questions.
Plus, since we went towards the end of the school year, they missed a lot of the special activities like field day, meet your pen pal day and field trips.
Our school doesn't have a vacation policy and I am starting to think that maybe all of the extra homework was their way of detering people from leaving.