Idk I like to hit assassins buring force shroud with my saber strike if I have nothing else better I can do.
Honestly the Sorc/Sage melee attacks are the worst in game. They don't benefit from your main stat and can be dodged so they do no damage and also are kind of unlikely to hit.
Bascially saber strike/trash is only for the LOLz
I thrash for the luls if someone is in my face sometimes. It usually hits. Always fun to use right as you finish someone off! Looks epic!