I have no doubt that plugs or plugs + muffs will give superior protection against hearing loss. I guess the real benefit of going with $600 electronic plugs are that they are custom molded to the ear, plus you can hear when there are no shots being fired. That would be difficult if you have plugs or muffs on.
As a student, I would want to make sure I hear the instructor. As an instructor, I want to be able to hear my students, too. This is also a benefit when I'm hunting.
Decisions decisions.