I found the Ir plugs maintained a snappier throttle for a longer time.
The standard electrode ones seem to "wear out" sooner and the throttle response becomes mild.
I had the IR ones in for 2 years and replaced them with the standard ones. The standard ones didn't seem as peppy right from the start.
I will be throwing a new set of IRs in the SE this winter.
Life's short...ride far
Over 2000 plated dirt riders...Digg'n up the dirt every other day, all over BC