I agree with Stealth
Speaking from experience, it's much easier on the kids to not split the school week up btw the two households. There's many reasons for that, but includes the kids, the teachers, etc. My ex and I used to do Sun-Sun, but after awhile we figured out that it's more FUN to pick up the kids Fri, spend the whole weeknd doing things, THEN start the school week, and drop off Fri. It's definitely an adjustment to not see your child for a whole week, and probably more than you think you can stand in the beginning, but everybody adjusts - and in the end, it's more to the child's benefit not to be shuffled off every 3 or 4 days. They won't feel like they have a "home" constantly switching. But of course, that's just an opinion......