I am a college professor--and have also taught grades 4-6 and HS in the past. I take my kids out at will (they are still young, K, 2nd, and pre), and I plan to continue to take them out. Right now, they are all above grade-level/age-level, so I don't worry a bit. And as long as that trend continues, I will take them out.
As an educator, I have seen kids and young adults miss a week + at every level...and really, almost all have handled it just fine academically. Once you take out lunch, recess, specials, transition times, guest speakers, assemblies, etc. the amount of time each day on academics (for elem and middle school) is about 2-3 hours at most. The parents have a lot to do with it as well...bringing the work you can, or having them do some sort of "project" or report for school about their trip, etc. I once had a student do "Mickey Mouse Algebra" while she was gone...it was hilarious! But more importantly--for the first time ever, she UNDERSTOOD it! You can make it work.
My best tip--instead of getting "caught up" when you get home...get AHEAD before you go. The kids will be motivated to do it so that they can go on the trip (and you can use all kinds of incentives...special souveniers or meals, etc. if they get their work done before they go...) That way, no stress on the kid (or you) and you can go on your trip without it hanging over your heads.
However, what an earlier poster said is true...one size does not fit all here.