S.T.
Both of my sisters were divorced with teenagers involved. both of them intentionally set up their hosueholds within walking distance of the former spouse. In one instance it was my BIL's kids - hi sex-wife lived down the streetes so the kids basically had two houses to live in and when they were younger they alternated weeks. There was always lots of back and forth and some confusion about where their favorite shirt was, or hairdryer, homework etc. My other sister was on the opposite side of the same neighborhood - and her kids did the same thing - back and forth alternating weeks. In both of these situations it worked out becuase the kids didn't have to be driven to the other's house if they forgot something, etc. All of these kids are now grown up - soem are married with kids of their own, some are just out of college, etc and they all seemed to do well - becuase their parents didi what was best for the kids - not what was easiest for them.
On the other hand, my husband's brother has a situation where his child's mother moved about 45 minutes away becuse it was more affordable. So his child is at his house every other weekend and on thursday nights. His wife has to drive his child to school on Friday monrings - 45 minutes in each direction. His daughter is still only about 10 so she's still willing to do this back and forth thing. But I suspect as she becomes a teenager that will change.
The best situation for the kids (and lets face it the kids didn't ask for this divorce thing and it's the toughest for them having to go back and forth like yoyos) is for the parents to live within walking distance of eachother. It may not make the parents happy but you asked about what's best for the kids.