It is somewhat lackluster as it needs the user to take a fixed amount of damage to activate this skill. In our current card pool, there's not many cards that can make use of this skill. Other than thinning your deck, there is no other notable benefit.
300 LP recovery does appear lackluster at first; remember, however, that Bakura's ace card, Dark Necrofear, relies on Graveyard manipulation to fulfill its SS conditions. Discarding from the Deck allows him to simplify the process.