So in reality it is not like oil so much
Actually, what I was pointing was that usually most who have an opinion have no empirical evidence to back up that opinion. For a lot of times it's brand loyalty. A "feel" for what they think is going on.
How many times have you heard or read guys say they put Brand A in their daily drivers, replacing Brand B plugs and "it's running so good I'll never go back to Brand B," without thinking about what they've just stated. Of course, Brand A plugs are going to be better when Brand B plugs when Brand B plugs have been providing spark for the past 100,000 miles. At that point, just about
any plug is going to do better than the tired old worn out ones.
That's where my comparison to motor oil was coming from.
Like I said, I've had bad experiences with Autolites, usually in the reliability issue. I've heard good things about them in a performance applications, on 1/4 mile at a time. But since my customers aren't driving a quarter mile at a time, I have to worry about longevity issues, too, to ensure the car isn't coming back before the next oil change with yet another misfire associated with broken plugs.