It has some flaws but it achieves redemption through a good story and a great setting.
I will not go into much detail about the story but I will say that it has all the usual Bioware traits (like major plot twists and romances). It all comes down to your character questing for more information about his past and reestablishing the great balance of life (you know, life-death, ying-yang, good-evil, divine-human); there's a lot of soul traffic going on in this game so it's pretty complicated. That should be enough info without giving away too much. Bioware also managed to create a nice set of NPCs to accompany you. Each of them has his/her own, unique personality and you are bound to find one that you like. The NPCs are certainly one of the game's strong points. About the setting: some will like it, some will not. I personally like chinese culture so for me it was fascinating. It's all about preferences here, not much else to be said.
Of course, a good story is told mainly through dialogs and Jade Empire manages to deliver that too. Those who have played KotOR will feel right at home with the dialog system... and those who didn't will become comfortable with it pretty soon because it's accessible and thanks to the good voice acting, also easy to get into.
I wanted to put the ruleset into the flaws category but decided against it since it's friendly for newcomers. Bioware employed a very simple rule system that lets you put points into your attributes (body, mind and spirit) and into your fighting styles (you start off with a few but learn many more along the way) at every level up. Also, the game doesn't have an inventory system, just some slots where you put gems that enhance your powers. This might be off-putting for a role-playing gamer but it makes Jade Empire a good starting point for those who are new to the genre.
Now for the flaws: the game is very linear. Very linear! You don't have much of a choice on how to play your character: you are either good or bad, just like in KotOR. You will have a few morally difficult situation but they are rare. Simply put, Jade Empire isn't too solid on role-playing. Also, the environments feel a bit cumbersome in some places and are generally linear. The good thing is they actually look great. I'd also like to mention combat: it's real-time but it doesn't feel particularly satisfying. Still, the many styles of combat sort of redeem it because certain styles will not apply to certain enemies, requiring you to change the approach a bit. It's nothing special and it would have been even better with a little tweaking (specially regarding difficulty) but this will do too.
So overall, Jade Empire offers you a nice escape from your usual gaming routines: if you like hardcore action then here's a little depth and story, if you like heavy stat-based, turn-based games here's something more simple and relaxing. It's particularly friendly for casual gamers and gamers who are looking to begin playing RPGs. It also delivers a good story and a great setting so I'd advise you to give it a try.