A lot of famous streamers doubted this card's potential when it was revealed (I'm looking at u, Trump!), but as the current Kobolds & Catacombs meta settles in, it looks like this is one of the most used cards in constructed decks. Its arena potential is also amazing, as you'd probably pick it most over the time over other 2 options.
So now that we know it's a great card, it's funny to watch some of the reviews it got right after the reveal:
Lightforge Arena Score: 160
Cost to craft: 400 dust
Current Tier 1 decks that include it: Tempo Rogue, Aggro Paladin, Murloc Paladin.
Worth it: Definitely!