The amount of content added to the game is immense. I'd call this an expansion rather than a DLC. It's even better than Enemy Within in terms of new content added, to be honest.

With the existing DLCs also factoring in, the game has quite a bit of replay value now.

And whatever they did in terms of actual optimization, the game runs so smooth now. It's almost as if the whole game was re-built on an improved version of the engine. I'm not sure why they just didn't patch the base game and fix the performance issues there, might be a technical thing I'm not aware of, but WotC feels good and smooth... unlike the base game that crawled like a dog with its hind legs amputated.

The only gripe I have is how almost ALL mods are broken, even those that are cosmetic-only. I'm not even worried about the character pool being empty (you can port them AFAIK, actually, from the old XCom2 folder under My Games to the WotC one). At least I'd like to see the laser rifle weapon-tier mod (from LW2) re-built with the WotC SDK.

Get it, it's a fresh take and you'll definitely want to re-play the entire campaign.