I live in Wake County, NC, a part of the country where school districts are county wide, not segregated by town (we've also made the news for recently doing away with our diversity program, but that's another story).
Currently, a number of Wake County schools utilize the year round calendar to manage the massive growth the county experienced in recent years. While there are a number of positive aspects, and while it works great in theory, it is a nightmare in practice.
My children are in a school with a year-round calendar. Having 4 tracks, each with its own schedule, allows for 25% more students in the school because 3 tracks are always in, and one track is always "tracked out"--each track is staggered and has its own track-out periods. It's great for working parents, who don't have to plunk down 12-14 weeks' worth of daycare costs at once during the summer. Plus, tracking out 4 times per year means there's a fall and winter trackout, providing great opps for bargain vacationing. Plus, students on 2 of the tracks get only one week off between grades (school ends late June and resumes first week of July), meaning there's no lag/gap in learning (as the teacher quoted in the article notes).
HOWEVER.....as great as this sounds, there are major drawbacks.
First--you are not guaranteed the track you want. Second, tracks are not assigned by neighborhood, so the other kids in your neighborhood are more likely than not to be on a different track, meaning 1) they are never going to be in your kids' class with them, and 2) they are never going to be on vacation when your kids are.
Third, the tracks expand and contract according to school capacity, meaning there's no real stability for your children. My children started the school on a smaller track and had the same group of kids in school with them every year (there was only 1 section for their track). Then, this year, there were not enough kids going into 5th grade for my elder child's class, so the principal opted to "collapse" the track and relocate the kids in her class to the other 3 tracks (and had to move all the younger siblings with them). My kids effectively lost their summer vacation (have been in school since March and will stay there till September) due to the change. Furthermore, my youngest was jerked from the only group of kids she's known at this school into a new class with total strangers. At least in "traditional" schools odds are high that you're have at least 1-2 friends with you each year.
Fourth and finally, there's no guarantee that family members' children will be on the same track--so scheduling family vacations or helping with babysitting, etc. is impossible with my kids' cousins.
I think the simple answer is that there is no simple answer. However, we do need to offer financial incentives for teachers to work in schools that have low test scores; we need to pay teachers more and offer more than lip service to show we value them; and we need to stop cutting valuable programs like PE and music, and we NEED TO OFFER NUTRITIOUS SCHOOL LUNCHES!!!!