I'd also tried some of those ballistic-material suits (don't ask how many years ago that was) and, I'd suspect that they've improved, but after having worn only leather . . they were "dirty".
The air smoothly slips around leather.
The wind grabs hold'a those ballistic suits'n tries to drag you off the back end'a the bike.
Lots'a touring'n cruiser guys are very happy with the ballistic suits, but to a sportbike rider . . kind'a like screen-doors on'a submarine.
Good leather gives me that snug, secure feelin' tha'cha get from'a good pair'a lace-up boots . . all over.