Flights aren't cheap (July...). So SW r/t is 800$ for 2 tickets, UA is ~1050$.

Cash flow is not an issue, and I will fly with the family a few times in the coming years, so I'm mostly looking to get the best value for the miles/cash/chase points.

It seems to me Chase might be the way to go (500 points for 800$ is 1.6X, which is a good ratio for UR). Whereas UA miles might be better used for saver awards in the future, or routes that don't have cheap direct alternatives.

Am I right? Am I missing anything?

Regarding the flights - both are same length (nonstop) and on the same hours.

UA is 100K (79K miles I have there + 21K transferred from Chase)
SW is 50K (all transferred from Chase)