Originally Posted by
Hollywood
Memory's Journey is one of the absolute best cards in Dredge's sideboard right now. I even main-board one because of its multilateral functionality. Leyline of the Void isn't worth mutating your opening hands over, nor is it necessary to dilute the quality of your mulligans thereafter. It's just a stale answer that really does the player using it more harm than good, IMO.
I've always likened the card as being a tool for people who use it out of desperation and fear in losing to match-ups where just about any form of graveyard hate is acceptable, except the person playing it is willing to stake his or her end-game by weighing how good Leyline really is at times when it's all they've got. The difference with Leyline is that it is easily answerable against a prepared opponent. It's the one sideboard card I fear the least because it is already doing me a favor in helping me mutilate my opponents' hands to find it, if not retarding them at the same time. They need to find one out of the four they boarded in at the cost of ~one card per hand. I have to find one of the six ways I can answer it with eight filter spells - all at the cost of exactly one mana each.
A good Dredge player will always have a sideboard prepared for Leyline of the Void. Memory's Journey, however, can legitimately cripple an opposing Dredge player by hitting key cards at key times - more than once - and acts as a form of protection for your own cards.