There is a decent amount of playtime to be had from the Knights Of The Nine component of this package.
The only problem I noticed was that the newly recorded dialog can sometimes be a bit hard to hear. Also the quality of the voice acting isn't up to the same standard as the original game, even though it's done by the same actors.
I have completed the main quest in Knights Of The Nine and I have to say the reward is worth it. You earn a set of armor and a couple of weapons that are most likely better than anything you are already using. In fact I'd say that while you have it equipped you are almost invinceable.
One of the interesting things about the new armor and weapon set is that you have to be really careful about how you play. You can't actually be kicked out of the Knights Of The Nine, but trust me losing this armor and weapon set is an annoyance if you want to wear it again…
Overall I'd say this package is worth getting if you don't already own the downloads, but if you do you may get better value from the standalone Knights Of The Nine addon.