It has the same issues as the base game. Copy/paste assets, pointless fights with way too many enemies at once, etc.
It's decent but nothing spectacular. Nothing close to Artorias of the Abyss.
you say that as if AotA didn't have reused areas or enemies (Royal Woods, the Scarecrow-thingies and Stone Giants = reskinned Darkroot; Chasm of the Abyss = reskinned Tomb of the Giants).
That doesn't mean it wasn't excellent, though. 'Cause it was. Them boss battles were glorious.
Haven't even finished Sunken King myself, though. Other things going on in my life at the moment for me to play DS2.