I am drawn to the 190-210m range when I think about it. Next weekend could well be the biggest weekend in box office history and Trek is right in the middle of it. Strange move by Paramount.
If Fast 6 is huge enough, that could mean there are tons of sellouts and people decide to go see STID instead. Being second choice would be a good thing. Those people that see STID be considered "spillover" from people who couldn't get into Fast 6.
This happened with "Twilight: New Moon and "The Blind Side", and both movies ended up doing good.