Originally Posted by kuppy
So what's the deal with the dlc?
I heard a rant that you get a extra location on the map that you can always visit which in the end means that you can grind (kind of game or at least the original conecept breaking). Is that true?
Any DLC chapter is fully replayable (and, unlike Bonus team battles, they give experience even if you play on Lunatic and Lunatic +). So, yes, it's true that you can break the game by grinding through DLC.
Is the dlc worth to spend money on / does ot add something really game adding?
Every DLC is a standalone chapter with extras. There are two DLC maps that come with new classes, so you might want to check those. 4 of the DLC maps come with new skills, there are also three maps made for grinding (one to easily get gold, one to easily get experience and another to (not so easily, but still quickly) get copies of otherwise unique weapons.
Many DLCs also come with new characters from previous FE games, but they're basically just pre-made Avatars with some extra skills (and have no story or dialogue after joining the player). The later DLC maps also are often harder than any story maps, so if you like grinding, they're basically the only things that will put up a challenge.