Currently secret hunter is a good anti-aggro deck because you generate alot of tempo with cloaked huntress and you have rexxar as a wincondition. Against control or combo however, this archetype is too slow because the opponent doesn't have to trigger your secrets and zombeasts are usually not fast enough to kill the opponent before they play their superior wincondition.

This will change with the release of Zixor. You still play the secret shell (including unnerved spellstone) to succesfully combat aggresive strategies, and instead of relying on rexxar to stall out the game and still lose to control/combo, you draw your prime zixor with Scavengers ingenuity and beat them with four 7/7s. 

Nine lives can be used defensively with mad scientist or offensively with zixor.