It is worth wearing the hearing protection if you're going to be operating for a long time, especially running an implement that is PTO driven at high throttle.
The 3M product is good but has flaws. One thing is your music volume gradually turns down on you against your will, and 3M notes this is to keep your hearing at OSHA-approved levels. After so much time, you 'aren't allowed' to hear music at a set amount of decibels. That annoys me. Another flaw is the material on the ear cups will gradually crack and break down with repeated exposure to sweat and/or rain. As someone who works outside swinging a trimmer in the hot sun for quite awhile on end, mine got both frequently sweaty and wet. They did last a few years before gradually falling apart. Also, the ear cup adjuster rods often break the plastic they adjust in, and even when new don't provide a lot of tension holding these things on your head.
The IsoTunes version addresses all these things, but the 3M has better, more intuitive controls and the battery life is better. Trade-offs, trade-offs.