This show has some good things going for it and some bad things going for it, but in the end, it's primarily about getting you to like the characters, then making you watch those characters suffer. Personally, I enjoy the cathartic process of characters making mistakes, suffering, overcoming their problems, and becoming better. If you don't enjoy this, you won't enjoy this show.
There are certainly a few downsides to this show. They overuse the CG a bit in combat, which is never ideal. The plot hinges a bit too much on coincidences. Some of the characters are a bit flat--in fact, I might go so far as to say Cheng is the only character that's really compelling.
Despite all of these problems, I find myself greatly enjoying this show.
