Good Electronic Earplugs? Not muffs

Take a look at the ESP models. On the pricey side but can be worn all day and definitely work. I wore them for 8 to 10 hours a day for three days at a precision rifle school without any discomfort. I have experienced hearing loss and have constant tinnitus and wanted to protect what hearing I have left. Several people on the Hide including range professionals recommended them so that is what I went with and have no regrets about doing so.
 
The ones built from a mold made of your ear canals will stay in without problems. I don't wear them as often as Sordins because your ears and skull also conduct sound. As much shooting as most of us do I do not believe an in-the-ear electronic system provides as much protection as muffs. Unless you have specific needs for them I'd suggest you stick with a quality pair of muffs like the Sordins.

This from someone that has upgraded his ESP plugs twice. They are nice, but I don't think they offer you the level of protection of muffs.
 
I have the GSP-15, they are the civilian version of the EB-15 (no difference in performance) I found them to be great outside but when a guy was on the line with a serious muzzle break my ears were still bothered and I had to go get my earmuffs.
 
How are electronic plugs any better for protection than foam plugs? 3m foam plugs typically claim to offer 30db of protection, but the etymotic link, to me looks like they are only offering 15db of protection. Am I reading this wrong?