For those who enjoyed the first one, this one is also good, but not quite in the same vein as that one. The first one had some comedy and comic relief with Keystone Cop / Jackie Chan style chases, and this one has pretty much none of that. It is a more serious story about Tien's background and how he came to develop his fighting abilities. The story is fairly standard fare for fighting/action movie, no surprise there. Just like the other Tony Jaa movies though, you are watching this to see the over-the-top fight scenes and this one definitely delivers on that front. A few scenes nearly set the standard for me as he incorporates a variety of styles into his instead of just using Muaythai against a variety of styles in this one and that made it feel fresh all over again. A few are definitely the kind I had to rewind and watch again! The bad part: it appears to be a trilogy. Think Empire Strikes Back.
The audio quality of the dts-HD MA track is excellent on this one - great LFE and a lot of stuff moving through the room to the surrounds. The video quality is very good most of the time. The movie overall is dark and does have some minor issues in some scenes. I can't knock this one as the video quality of his previous films is rather poor and this one is immensely better comparatively.
I give this one a 3.5 / 5. For fans of Jaa, highly recommended rental. For others who haven't seen the first one, you might want to rent that one first even though this is the prequel.