you gain sidestep and sprint with it. if you're not using it to kill the other guys army, you're doing it wrong.
It works for cavalry, and jacks with mutiple attacks - if you ask me, he's best off with character jacks like Beast,Drago or Big B. Use his to bash your way through a screening line of infantry, generally with the aim of getting at the caster as part of an assassination run. hit something. sidestep into something else. hit that. sidestep into something else. hit that. repeat. and at the end you can sprint away from retaliation, and if you're smart, set up a second alphastrike.
great fun with fenris too - charge. inflict impact attacks. charge attack (+2 to hit) kill something. berzerk with fellblade 1 until everything is dead/you miss, sidestep 2", kill something else with fellblade 2, berzerk and at the end, sidestep/sprint either forward into something else, or elsewhere to avoid retaliation. think about it. with fenris, and with dash up, thats 11" of get of of jail movement after he's shredded a whole squads worth of infantry.
The feat is situational, but extremely useful. Vlad3 is a pretty solid caster.