Are they the same as the regular cards with different art or do they have different stats and capabilities?

If i'm not mistaken, they are the exact same with different art. Stats are the same, abilities the same, just better (other) pictures.

If you are referring to the promotional 'double sized' cards, they're nothing special. The ones I have from League play have the exact same art. In fact, the Boba Fett/Han Solo card only displays only the standard attack symbol, instead of the (accurate) attack symbol that indicates a 360 firing arc or a backward firing arc. It's not a big deal, I don't see anyone saying that "if you use the full-sized card, you can only attack with a standard firing arc," it's more of a thing you have just to have, rather than to actually use to help you in the game.

I think he's referring to the Season 2 cards featuring Wedge and the Black Squadron Pilot. I'm about to win me some today, but I think Syleh Forge is correct.

You can find images of the alternate image cards around online. They have the same stat line just different picture. Wedges card is a still of him in the cockpit from the movies.

The only real difference is the art and the quality of the cards. The cards are made by a different manufacturer than the originals, they are more shiny and the colors more vibrant. They come from a print on demand vendor that is why the kit ones have to sleeved in the other games of LCG cause they are off colored just a tad and stand out.

I was referring to the Black Squadron and Wedge cards, but the info on the over sized cards is appreciated as well. I'm just getting into the game and I didn't know if these cards were worth getting or not.