I found this expansion to be disappointing.
I first tried the expansion with the character I finished the original with. I practically sleptwalked through the entire expansion. My paladin, approx lvl 20, and zero trouble going through it.
Next, I tried it with a brand new character. First I tried a monk, and it was just too hard. Next, I tried another paladin, and it was still extremely difficult to get through it.
So, for someone that was looking to move forward with a character that finished the orignal, I can't imagine this expansion will offer you ANY challenge. I think I finished the expansion in a few days. And if you want to start a new character, be prepared to really work your bottom off.
Here's hoping the next expansion is better suited to either roll.