"Preventing cards from being placed in the graveyard" might be a bit hard to understand, but it refers to removal that exiles from the battlefield, or removal that returns cards to the library or hand
It also stops graveyard decks from looping or playing Living Death, which can be a lose-condition for Voltron builds
The back side is a regular card back
The only place where they rank far behind Dragon Shield is the rip test
Even if you can't necessarily put the land straight onto the battlefield, you can alternatively use creatures such as Sylvan Ranger, Borderland Ranger, or Civic Wayfinder to get whatever land you need into your hand with ease
The Lord of the Rings Commander decks are still widely available despite being released three years ago, and their prices have remained close to MSRP