This card is a really nice combo piece, and on its own it's pretty good too. If we presume that this is in a green ramp deck, then it could be played on turn 3 or even turn 2 depending on the deck. At that point, the caster will probably have at least 4 cards in hand if not 5, meaning that this card makes a decent number of Saprolings for its cost. Now, as a combo piece, it works really well with cards like Biomantic Mastery, Distant Melody, and Sigil of the Nayan Gods. For the card draw cards, it effectively doubles your hand and with Sigil of the Nayan Gods it becomes a pseudo-Empyrial Armor. This card isn't meant for every green deck though. Decks that can't keep their hands full or that don't like gribblies won't appreciate this card since it won't do much for them. But, all in all, it's pretty useful in most situations.
Pros: Makes a fair number of creatures for its cost
Cons: Sorcery speed, may not always be useful