The only reason to watch this is because you enjoyed the original and want more stylish badass action, violence, and more style. Come in with the same expectations as the first and you'll most likely enjoy it all the same. Expect more than that and the flaws will glare back at you in distain as you would do to them.
It's more of the same, except now Afro has the Number 1 Headband he got from Ron Perlman (Justice) at the finale of the original. In a nutshell, Afro is in solitude after getting the headband but loses said headband to Lady Sio and needs to get it back as well as stop her plans. That's pretty much the plot right there, just short of explaining the plan. It's there for Afro to have a reason to kick ass and look stylish while doing it. The story or writing don't matter much, as the fighting is what it's all about.
Same old style, same old visuals, same old amazing stylish goodness. It looks good, it runs good and it looks beautiful. As stylish as ever, it keeps up with the original and for the most part, nothing has changed; which is for the better, as the original looked amazing. Also of note is the opening, which looks damn amazing and feels kinda old-school.
VO is just as good as before, except for the lack of Ron Perlman. Music is pretty much as good as before as well, especially the theme to the opening. And it works wonders when it plays again later on.
Afro now has a beard. Apart from that, everything's just about the same. Lady Sio wants revenge and there's some backstory to it and to some of her partners-in-crime, but that isn't really important. What's kinda/slightly/sort-of important is a boy later on, but to go into it might spoil it. But remember; why did Afro kill in the first one? Was it because they hindered him in his quest for the Number 1 Headband? Probably, and that's all I have to say about that.
As usual, first and foremost is the action, violence, badassery and style with a "plot" to help move those four aspects along. And because I should mention it at least once; fan-service, mainly in the form of the main villain no less. It's like two peas in a pod, with the other pea being the first one; they're nearly identical.