Jade Empire was... okay, in some ways. I actually thought the plot was a little more interesting than the standard BioWare setup, with characters who had more believable and complex motivations than just "I'm Mr. Badguy." The setting, despite occupying that weird valley between horrendous and offensive caricature and at least somewhat accurate to mythology and history, was also a very welcome change of pace, even if they didn't do as much with it as they could. Combat was also not that bad, nothing special but it got the job done and certainly had more depth than standard button-mashing. Some fights near the end of the game got quite hard if I recall correctly.
My number one complaint with Jade Empire is pacing. It starts off very humbly, introduces you to a nice first town and a wilderness area, both of which are reasonably large and have a lot of content. From there there are a couple of dungeons to explore (cannibals, the heavens or whatever, etc.), and the game really feels like it has a sense of direction. After that, you have the pirate fortress, and the game's biggest part, the Imperial City, where the plot (as I recall) kind of just grinds to a halt for several hours as it dumps like 10+ hours of optional side content on you. This portion of the game is, comparatively, huge, and there was really no reason for the location to be so big - the story simply did not justify it.
However, after that you end up in endgame mode almost out of nowhere, and the game becomes super-linear, rushing you from place to place and having laughably short dungeons and only a few small gameplay segments. There's even one of the most ridiculous mini-games ever in the form of that awkward side-scrolling beat-em-up. All the momentum built up over the course of the game comes crashing to a halt. You have five hours of endgame to get through, too, which feels way overlong. I remember thinking "is this the end yet?" over and over, knowing that it wasn't but every part of the game acting like it was about to wrap up, hour after hour.