daze
big difference man! strut bars are used to stiffen up the chassis, preventing flex.
Anti-roll bars/ sway bars are used for reducing roll (during cornerning) between the left and right suspension. It's actually a torsion spring, connectiong the left-to-right (or right to left same)
when one side is loaded (while cornerning, and you'll experience roll) this ARB will transfer the load to the other side and TRY to equalise the both, reducing the roll, and getting the other side to work/grip as well.
too thin produces little/no effect
too thick produces understeer :D
so must have BALANCE :)