I've used plugs or muffs (sometimes together, but only because of crummy muffs) for years. When I decided to spend the bucks on a nice pair of electronic muffs from Dillon Precision, I was converted. Now I'm an evangelist for electronic muffs. This particular pair gives plenty of noise reduction for any of the rifles or pistols I use, including the occasional .50 BMG (I've never come home with a "ring" in my ears--something that cannot be said for the days I used cheap, passive muffs). With the microphones you can hear a pin drop, or the breeze rustling the grass, etc. while wearing them, and in stereo, so you have some degree of directional perception. The profile is such that they only rarely (but sometimes) get in the way, and even then its a minor issue.
Given the choice I'll never use anything else.
There is only one thing I dislike about muffs: The're not practical with a wide brimmed hat, so I'm forced to use a baseball type cap.