I visited the US in the past (hell, me best trip ever was an epic coast to coast with a Marine friend) and I'm aware of the differences.
Cultural differences are ok, this is why we consider moving - and why I moved a lot around in the past.
My main concern is about getting to an age where I can't really afford severe financial missteps.
Our "purchase power" here in Berlin is very very high and as much I consider Berlin a messed-up city the overall quality of life is stellar.
I can afford to stay put for a while (in fact, that is the plan in case we move, so I can support my kids with school etc.), but I want to make sure that, when my stay at home dad period ends, I can get to an income level that is close to our situation in Berlin.
Doesn't have to be the same, but I don't want to end up loosing money over the move.