Originally Posted by
Jesture
I think this really sums up my problem with new Jace.
The grindy decks mentioned (Shardless, Miracles, Lands) either have great sweepers that make extra creatures a liability (Deluge, Terminus), or simply don't care about a looter (Lands is patient, they wouldn't care about Jace before they've established a strong board presence, and at that point flashing back pump spells without an infect creature seems... not ideal) (Also Rest in Peace is much better against Lands, and you can't exactly run both.)
This is compared to Sylvan Library. Consider a standard Library draw:
T1 Land
T2 Land, Library
T3 draw two extra cards
T4 another two cards, you're up 4 cards on your opponent at this point
Versus the optimal Jace scenario:
T1 Fetch (1 card in graveyard), Hierarch
T2 Fetch, Jace (2 cards), maybe Ponder here? (3 Cards)
T3 Brainstorm, fetch, loot for 5 cards and flip Jace, nothing of note to -2 at this point, maybe +1
T4 With the -2 ability on a cantrip, you've better one extra card
Keep in mind you're not favored to play long games against these decks. Jace feels way too slow in these matchups requiring at least 3 turns to go active, providing one loot in the process and one flashback as the end result. Sylvan is flexible, it's going to give you a top spin once per turn plus the option to just jam card advantage if you're looking to close out the game, both of which seem incredibly important against grindy decks.
So maybe his place is against fair creature decks, which I wouldn't even bother playing Sylvan against. If that's the case, I'm doubtful that there isn't another card we could play in this flex slot that would be better.