You only get to do it once
Gond Gate has the ability to make your Gate lands more powerful by allowing them to enter untapped, and when it is tapped, it also grants you a single mana that one of your controlled Gate lands could produce
Underdark Rift is a Land with dice roll synergy, as by paying , and exiling it, it let us roll a d10 at sorcery speed, to put target artifact, creature, or planeswalker into its owners library just beneath the top X cards of that library, where X is the result
Japanese Pokmon cards can be worth significantly more than their English counterparts
You could offset this weakness with Skullclamp but I prefer to make a purer deck and adapt my play in this sort of situation
With the non-mythic lands, you were exchanging a land for a tapped land that could be a spell if you don't need it