The Chronicles of Riddick is a good reason to watch Pitch Black because director David Twohy finally got the money to make a complete movie. You can see his ideas now well developed and supported by good special effects. He patches most of what was lacking in the first installment, except for one dimensional characters, but my guess is that's intentional. There's also a number of logical flaws still left in the scenario.
In this chapter, you get fully fledged and totally original ideas, that really transport you to a different world. and by the end, you simply want to know more about that universe. What other incredible things might be hiding there?
The acting is on par with the previous flick, average, but no more. The dialogs are maybe a bit better, but you could starve a mouse on the difference.
It is simply a feast for the eye and the imagination. An action film to give you adrenaline rushes. No more.
Give your brain a break, watch it, and have fun.