I don't know. I'm probably weird but I actually liked how the add-on seamlessly integrated with the main game like an add-in. I also really liked this new oriental-style world (Tie'Shianna) as a welcome change of scenery from fantasy land. I don't think I've finished the expansion content yet. I'm at the point where -very minor spoiler alert- … … but so far so good. Tie'Shianna has been a fun and very visually pleasing distraction for now.

All in all I believe that if you can get your hands on the River of Time with Phileasson's Saga included (like a Gold bundle) then by all means get the whole package. I wouldn't call the add-on content exceptionally bad. It may be relatively bad if you have to pay an extra $20 just for the add-on but if you can get a bundle of the original game including the add-on for a reasonable price then I'd call that a great deal.