Given exactly the same price, and same total amount of memory, of the same specs.
It is very slghtly better to run 2 sticks, there are less slots to address. Timing is slightly reduced when running with 4sticks; but it is a very minor difference.
Use it only as a tiebreaker. If choice is between 16gb vs 8gb; or saving a decent amount of money, use one of those factors instead.