Ha! LOL We are taking ours out (8th, 4th, and 2nd) in November for 3 school days total (5 day trip over a weekend). I would take them out for M-F 5-day trip, and honestly would rather so I don't have to fight weekend crowds, but it was ME that didn't have the time to take since it was not originally in the vacation plans for this year and we already had taken two smaller trips in March and June.
Two years ago, we took them out for a full week. I notified their teachersahead of time. DS1 was in 6th grade, and I never heard a word from any of his teachers or principal. DD was in 2nd, and her teacher emailed back "Have a wonderful time! I wish it were me going!!" DS2's teacher said "Thanks for letting me know! I took my 3 kids a few years ago, and it was the best time of their lives! I will have a homework packet sent home so he can work on it during the trip".
I would take my kids out of school for an "experience" any time! Learning doesn't only happen in a classroom, and I have an honest belief that parents are not only the #1 teacher in a child's life, but it is also our responsibility to partner with the school and teachers to provide our children with a well-rounded academic AND social education. We take the time wherever we are to stop and use something as a learning opportunity, and amazingly, there are hundreds of learning opportunities at Disney World!