You don't have to use your state's sponsored 529. Sometimes there are tax incentives and sometimes not. Here in NC the performance of their 529 fund flat out sucked and the performance of another state's 529 would be better even without the tax incentive of the NC fund. Then they changed the 529 incentive here in NC so that if you made over "x" amount you no longer got the deduction.
I live in NC and am enrolled in the Utah 529 savings plan. Other well performing I researched at the time were the Nevada plan and I think Alaska. I've been getting a 12% return each year for the last three+ years on the Utah plan.
It isn't hard to research what the top 5 or 10 plans are. It doesn't matter whether you use your home state's plan or where your kid decides to go to school.
529 is actually one of the easier investments to choose from.
For me, a history of performance along with the Utah plan being managed by Vanguard was good enough for me.