Does that not sound like a super-abstract question to you?

I recognise it as asking pretty much exactly the same question as "an alternate several-thousand years of human history has taken place concurrent to, but separate from, our own; what's it like?", but the Many Worlds appeal is like saying "here is a blank canvas where anything can happen", while the equatorial wall or counter-earth scenario is like saying "here is a situation: how do you deal with it?"

I think that's what I meant by Many Worlds being too open-ended in my response to drethelin.