16
Standing on 16 would most likely favor the house because the dealer will bust less often. So if the dealer has a 6 up and you have 15 and he flips over 16, you're shit outta luck and lose.
The only advantage I see for the player is the fact that 17 could now win without the dealer busting.
It would alter BS slightly as now you would have a reason to be hitting against a 6. But hitting more stiffs vs a dealer 6 will most likely result in players busting more often, further adding to house advantage.
Generally think of it this way: If the house is offering some odd rule/sidebet to the regular game of blackjack, chances are it favors them.