The expansion is totally different.
At the website I provided you, click on the expansion..Sacred: Underworld.
The other thing that Plus did was correct a lot of bugs that the original had.like quests, especially the ones timed..that you couldn't do.
But, if you have Sacred, play that; I would download the patch for it as the patch fixed a few things.
Then wait and see if Underworld sounds interesting when some of us start playing it.
For me, Plus was worth it..and after having sold the original and wanting to play the expansion, knew I had to start over so did so with Plus.
It's a good game, I like the quests given and enjoy the characters..not so sure about the gladiator one(he's growing on me though), but I like the others..
The thing I dislike the most, is the constant re-spawning of areas you cleared..drives me nuts.
I like to explore a bit without having to always be fighting to take a peek in areas..but it's a fault I can live with and still enjoy the game.
Okay, playing today..Have to decide on which character I want to export to expansion.
have you decided yet??