Keri - increased hit rate for kicks
Atemi - increased damage/hit rate for hth, unarmed block, tiger claw, backfist
Nage - increased damage/hit rate/gc chance/gc affects for throw + throw assassins and hth warriors.

Seems pretty nobrainer to me because it's lag that kills.

That being said, I had Keri and Atemi assassins. Both times I pitied myself for choosing them.