>>138033585The DS Zeldas are ok games, but fall pretty short when compared to other games in the series.
Phantom Hourglass has a repetitive timed dungeon that you have to do again and again and again and again that gets on everybody's nerves and an annoying collection quest to completely power up your character, but otherwise the gameplay is solid and the dungeons aren't bad.
Spirit Tracks fixes everything that is wrong with Phantom Hourglass, but the train gets old fast and the later parts of the game are overwhelmed by fetch quests, though those fetch quests are optional. It has one of the better stories in the series and has the bro-est of the bro-tier Zeldas. The dungeons start off super easy but get more satisfying as they go, though there are not many dungeons in the game.
They are worth playing if you are a Zelda fan and feel like it, but both are pretty flawed and you are not missing much by skipping them.