Join Date: Nov 2007
Location: The Land of Jersey
If you were to take a pair of pliars and tried to break off a corner of some MDF, you'll see it breaks parallel to the edge. As far as strength after being milled, Naturally your thinest section will be your weakest, and my take on MDF is it's good for applied raised panels on walls, and occasionally the center panel on a set of upper cabinet doors.
I'm seeing a lot of MDF trim going into million dollar houses and it's mind boggling sometimes. For anything structural or load bearing, leave it on the stack and use wood.