Resistor is a beautiful piece of ICE.
Thematically I love it, flavour text and all, and mechanically it slots into NBN very well. Name a good NBN faction ETR Barrier and chances are you think of Wraparound and that's it, so Resistor is a very welcome addition. Here's a piece of ICE with a welcome rez to str ratio that gets stronger with each tag the Runner has, and in NBN that's insane.
To balance this the ETR subroutine is trace dependent, and at a base trace of 4 you'd better be sure to have a good reason to pay up if your link is low. This makes Resistor slot comfortably as a taxation for the Runner, offering that glimpse of hope that they can go through, but their active Surveillance Sweep could end all of that. A Resistor is designed to allow an electrical signal through, but slow it down, and that's exactly how it feels. Resistor will give away to the Runner that you're likely planning on tagging them, but it won't give away the intentions of those tags. Overall, a good piece of ICE, and an annoying one at that!