The big problem with max effort is that it's pretty easily won by a car properly set up to turn as it's a lot easier to gain a few seconds advantage on an autocross/road course than on a drag strip. Most of the cars running faster than mid-10's are not going to do well on an AutoX course whereas any DSM setup to turn can easily be made to run 11's without any compromises.

That being said, it also depends on the AutoX track layout as when they make faster (read: straighter) courses it's typically much closer.