Neck thingie
I love Harper. I really like the fact that they are fleshing out his character some - like the episode where he and Trance got caught up with that Nightsider. I'm kinda glad that there's a dark streak in him. Makes his character more interesting.
As far as his neck thingie, I've seen every episode three times (except last weeks, missed all three - rats!) - and as far as I can tell not once has that thing been explained. Rami mentioned his skin condition in the first episode, but not the interface.