If you are going to play the DLC, be sure to keep your before-Tartarus save. I bought the DLC and now it's collecting dust because I accidentially overwrote it and they made a dumb decision to prevent you to play the DLC with end game save. So be aware.
It's not worth it. The combat is blah. It's still free is you sign up for Xbox Gamepass though. That's how I know it's not worth the full price.