Having a wider gap for Iridium plugs makes sense if they spark at a lower voltage, so not stressing the ignition system as a whole.
Older members particularly with bikes may remember the phrase "big fat spark" as in easily seen. If you do the plug out checks for same with modern electronic ignition systems though you may well be disappointed. The lighter colour and shorter duration of spark makes them far more difficult to see in daylight even though the spark voltage is likely greater giving better combustion.
