I will admit, I was already a fan of Serenity, Riddick Chronicles and all that, so I did go into this film with a bit of predetermined anticipation. On the flip side, I'm not always that much of a Vin Deisel fan, in that he is somewhat mono-dimensional in his range of characters, but for the embodiment of Riddick, he does fit perfectly. As for the story and how it plays out, the pace is good, not too encumbered with gratuitous special effects and all that, but where it does fit, the CGI is well done and appropriate.
The one really glaring technical defect in this story is how everyone just gets out and starts walking around, breathing in the air without the slightest concern for differences in the atmosphere, microbes and so on, but this is a common flaw that is often somehow glossed over in many such stories, so I can't harp on that detail too much.
As for Radha Mitchell, she is smokin' hot here, not in a ridiculous or frivolous way, but as her tough, seasoned interplanetary merchant marine ship's captain character "Fry", she nails it perfectly. If anything, she very much reminds me of Andrea Osvart (see her as the Hungarian assassin "Gilda" in the film "Two Tigers").
Now, if these two ladies ever appeared together in a film, I would drop everything and go check that out in a heartbeat . . . but I digress.
In any case, I have no trouble with granting 8 stars to "Pitch Black".