Wow dude very nice. This is far more comic looking than your regular style. Is this a permanent style change or a style you will lock down for the comic? A name like Jack is good it think. You are right in thinking that a name like that makes him more real. Steve or Dave, Jack or John. The veins are cool, yet I can't help thinking they are a little cliche (don't ask me where from it's just a feeling, sorry) This style I think is definitely a goer for the direction you are taking this comics. Its a little more dark and can be taken more seriously I think than your older style. Don't get me wrong your usual style is great. But I think this will lock you down into the comic store and feel like home a bit more. I like the sketchy style of the line work. It has more passion and emotion in it. I think if you push this style you will more easily be able to communicate the character and what he will go through.
Originality: Fair (the glowing veins i'm not sure about)
Technique: Fantastic. I love the new direction in style. Be weary about loosing all the highlights though, Don't make everything so diffused. Try using highlights to your advantage to help accentuate areas of interest. I can appreciate this is a night scene though.
Impact: Different from your other image of "Jack" Last time it was strong and forceful like he is standing up for something. This feels more like you have caught him on a CCTV camera or something. Like he is on the run. Good over all impact though.