The major issue with Sower is that you can kill it easily, thus getting your stuff back
This is often the case when you are resolving an effect like Cathartic Reunion or Faithless Looting that draws multiple cards, as you want to go raw numbers first and can then decide on the last draw if you want Life from the Loam or a blocker
Combo this card with spells that allow you to steal creatures from your opponent's graveyard for max value
In the case where you have one or more copies of a specific rare card and the decklist includes only one, you will not receive anything for that card
Ultros, Obnoxious Octopus Ultros has too many teeth (though thats accurate to the games), and is a great card for limited with letting your midrange spells ice opposing creatures, while the 8 mana thing left to the realm of casual play in large
Lathril, Blade of the Elves and Kinnan, Bonder Prodigy are strong examples of commanders that benefit from a higher creature count in ways that make up for the inherent fragility of creature-based ramp