Originally Posted by Brightinly
I think BotRK is a good item, but come on, it has a melee rangeish cast. Ranged champions would need to risk their range to gain that extra HP just to probably get bursted.
The active is meant for when a bruiser or assassin gets in your face. You steal their some of their move speed and health so you are able to kite them until your allies can assist you.
For Ashe, Varus, and Kog'maw the active is a life saver. Not to mention it's an offensive item with a life saver, unlike GA or QSS, so it doesn't take up your defensive slot.