We also have access to the super-versatile Meteor Golem, Plaguecrafter, and Crush Contraband for problem artifacts & enchantments
The handiness of its ability to dig five cards deep and draw two cannot be overstated - especially for a deck like this where you need to look for combo pieces
Within 2 activations, you are already drawing 3 cards, which is already an amazing amount for a mana investment of 4 mana
The value you get from this two for one is hardly exciting
Otherwise, put it into your hand. Putting a card into your hand is nice, but you can literally win games by just combining Meren with Spore Frog, which you can sacrifice to prevent all combat damage for a turn - and only costs one mana
Youre a little lower to the ground because you want to cast creatures early and often, more than once per turn if you can help it