I read some reviews about the Howard Leight electronic muffs on amazon a while back and some users complained it didn't block enough noise. So if you do go for e-muffs, you may want to stay clear of the Howard Leight or conduct some more research.
People said when they used them at the range they just ended up going back to their earplugs. Then I remembered how I cant shoot a long rifle with big muffs, and decided I'll save $100 and stick to my earplugs