There is absolutely no comparison between younger kids and kids in MS/HS. Seriously, if you are worried that your kid will miss a week of kindergarten, then I suggest you prepare yourself for a very stressed out parenthood.
As mentioned in other threads, our twin boys go to private school (just finished 1st grade) so we don't have to comply with district/state regulations, and their school isn't impacted by their absence as far as accreditation goes. We choose to take them out of school for the longer cruises (EBTA, PC, etc), because we like the longer ones and I have no desire to go to the Caribbean or Bahamas. When we did Alaska, that was obviously during the summer, but the TAs and PCs are only offered when they are offered - I can't make
DCL change that based on my sons' vacation schedule.
I have a doctorate, so it's not like I don't value education. But I also spent a semester in Florence for undergrad, and everyone who has seen the amazing art, architecture, and culture of things like the Sistine Chapel, David, La Sagrada Familia, etc. will tell you that being there is a gazillion times more meaningful than seeing pictures in a book.
My sons don't have to make up work, so that is another factor. The teachers don't have to do anything extra. Instead, the boys write and draw about what they've seen and present it to the class when they return, along with cool stuff we bought. Their journals stay on a table for other kids to check out for a week or so.
I think everyone has an opinion and no one will change plans due to what is posted here. But I do like seeing what others have to say.