After looking at their cards, the players - starting with the first player - can choose to return any number of cards from their hand to the bottom of their deck (without revealing them) and redraw the same number of cards to leave them with a hand of seven
This means you can slap it on a Changeling like Mischievous Sneakling and put any creature from your top five into play
In case it matters for answering this question, I'm mostly interested in: Commander casual play (winning is not my main goal) multiplayer
Sadly the double green cost about offsets that and just leaves you with another very average filler card
According the Rasmussen, [the economist] let me know that, based on just the first printing of Zendikar Rising and Ultimate Edition , there are more copies of Marsh Flats printed in 2020 (so you can say that for any of the enemy fetch lands) than there are copies of, for example, Force of Will or any other given Double Masters mythic rare. Magic Fiction Returns
As any deck designer worth their salt will tell you, its all about the mana