Dunno about those specifically but I don't just use plugs on their own.

Either over ear protection or over ear AND plugs underneath.
Reason for that is bone conduction which can cause hearing damage even with the ear canal blocked by plugs, especially with louder firearms or indoor shooting.

MSA's Sordin line is excellent, and as a budget option either Opsmen's Earmor or Howard Leight's electronic ear pro are hard to beat for the price.