Spark plugs are INSIDE the engine. If everything is grounded correctly (it usually is not) then EMI from non-resistor plugs is not a concern. Unless you are a bunch of software guys like Hondata who can piddle with simple digital circuits but lack any real clue about electronics/analog theory so their shit gets raped by non-resistor plugs, solar flares, having your cell phone too close to the ECU, or something else equally fucking retarded. Their shit is laughably comparable to AEM's support of VR sensors in the v1 EMS. The Blueridge car makes 800+ while running an Ostrich on a ribbon cable (read: antenna) which is mounted six inches from a MSD HVC II coil (5-6 times larger than a Blaster SS, weighs 20 lbs or something) and a foot from a Digital-6 box. Welcome to what a PhD in petrochem with an IQ of over 9000 does as a hobby vs a team of talented average-intelligent coders who are too lazy to learn anything else and have to resort to suing freeware guys to keep them out of the K-series market because their product can't handle the competition.
Now, like Concept-X said, non-resistor wires will rape your shit like turning on a blender rapes an old school TV. Old farm tractors ran solid metal core plug wires and if one was running a quarter mile away you couldn't watch TV because they weren't designed to reject the interference.