I use electronic muffs mostly, Hot in the summer!!, I do prefer plugs for shotgun, so you can cheek the gun tightly, without the muffs hitting the stock.
I really like electronic muffs for hunting, especially in the Cold, they keep your ears warm, you can hear better, due to the amplification.
In competition, I use the electronics, and as a range officer, if someone comes to the line with very hot loaded bottleneck, cartridges with a 7 port comp, I use both, and turn the muffs off.
If all you use are plugs, the inner ear still gets damage from the mastoid bone, they are definitely better than nothing, but not the best. I do like the molded plugs, but the foam expandable, work well, are cheap enough, you can put 10 pair in your shooting bag, and 10 more in your vehicle, so A your never without hearing protection, and if someone else needs protection, whether at the range or at work, your covered.