My apologies Flu. For some reason I thought all your kids were in college. I’m trying to make you older than you are :).
Like you, I’ve been pretty happy with Vanguard for my own retirement and mutual funds so I just went with them for the 529s. I went with the “age” funds where they start out almost all in stock and now (for my 12th grader) are almost all in cash/bonds.
Like you, I’m not particularly interested in gaming the system. I’m too lazy for those games and I think the money is needed for those less fortunate. I don’t consider getting residency in another state gaming the system. Besides living there for four years, based on my experience, one often ends up settling down near the university or grad school. If the kid has a condo in that state, he/she really does have a vested interest in that state and is paying into it (ex: property taxes).
However, my brief research indicates that it is not trivial to establish residency for purposes of in state tuition. I’d be interested to hear from folks whose kids are recently in university if they considered getting residency in another state and if they were successful.