You know what another good thing is of fans seeing it a week early?
The film releases on Friday the 25th of March, the review embargo will most likely be lifted on a Monday the 21st of March (as per most films doing that including Man of Steel), and a lot of people (mainly fans that were eager to see the trailer in theatres) get to see it a week early on Friday the 18th of March.
So in other words before the review embargo lifts and tons of reviews flud in to judge the film we'll already have a basic gist on whether or not the films good before the actual reviews come in which is cool, plus we'll know which reviewers are BSing about their reviews.
So those that get to see it early on the 18th of March, please go to the BvS RT thread and predict what the film might get based on your viewings.