Just finished playing through the expansion my first reaction was that areas are more detailed then the orignal game, however Iwas a bit disappointed that character bonds and achievments didn't transfer to the expansion. For example I finished origins being queen but Nathaniel refered to Anora as being the queen.
As said the areas are more detailed my favorite area was Amaranthine every where you looked it was refined and polished to look real. Only drawback that this town is really small compared to origins or neverwinter night towns.
This expansion also offers some great battles, There is a fun battle againstt a lightning dragon that really reminded me of MMOs. Other fights had you fight with multiple bosses at once, while others had multiple adds spawning in the fights. Boss fights were all different and really enjoyed my self repeating them again.
About the main story is short, and didn't evolved much, in brief new dark spawn incursions that you have to stop. However there was a side story about blackmarsh town that was really engaging even more then the main story.
About characters I got to say I was happy to have the funny Orghen back, he always have good jokes. Voice over of all the main cast was good however Anders character was to similar to Alister it was like Alister became a mage.
Final point that the game still has many bugs and crashes occasionally