As far as plugs vs muffs, I think that with plugs, once the pressure waves make contact with your ear, the vibrations will easily continue along your skin making it easier for the wearer to still hear sounds even though they are MUCH quieter.
I had a Husqvarna helmet to start with, and didn't like it. I immediately returned it and bought a Stihl which I liked better. Unfortunately, about the 3rd time I used it, I set it down and knocked it off onto a hard surface breaking one of the built in muffs off the helmet. That was about 15 years ago and I haven't bothered to replace them because I found them awkward to use. I normally just use plugs instead. I've thought about trying to connect a set of plugs to my helmet, but never bothered.
Earpro is actually something that I'm constantly looking into. My lack of taking care of my hearing in my teens and early 20s has had its effect on me, but thankfully I started taking it more seriously while I was in college. My issue with both styles is comfort and being able to keep them on/in while actually working. If I'm wearing safety glasses (mowing, welding/grinding, doing construction, ect) the muffs become uncomfortable after a while because they are pushing against the sides of the glasses. Now that I'm wearing regular glasses daily, that has become more of an issue. I don't notice it at first, but after several hours, it starts to give me a noticeable headache that's difficult to deal with. I've noticed that the behind-the-neck style of muffs don't push as hard against my glasses and are more comfortable for me wear all day long. They also fit with my welding helmet on. For the past few decades, I've normally worn a hat with a full brim which also makes over the head muffs a no go for me.
Many plugs, on the other hand, make my ears sore if I have them in for several hours. Not to mention that if they are connected with a string, they tend to get pulled out by my shirt. The individual closed cell foam plugs have been the most comfortable for me to wear, but they are also the hardest to get in correctly (so that they stay put). I've tried electronic plugs and love the ones with built in Bluetooth, but they NEVER stay in very long. I love the idea, but the application sucks IMHO. I don't see how ANYONE on an active firing range could be happy with them, ESPECIALLY if they are doing any kind of running and gunning. I'd much rather have the same features in a behind the neck muff, but I haven't been able to find any.
