Actually in 3.5, I had a pretty nasty fighter.  Had the mage slayer feat and carried a longaxe.  He'd get into the face of a creature with spells or SPAs so they couldn't cast defensively.  If they tried to take a 5' step, he'd power attack +3 to make the longaxe a reach weapon for the round meaning they still couldn't cast defensively.  So they'd either have to forgo casting or take an AOO.