I have a set of the slimline Peltors.
The battery replacment is "an interesting exercise in dexterity" as the batteries go inside the muffs individually & to open the muff body is a project.
The slimline, which I wanted particularly so I wouldn't have contact with the rifle stock, are too slimline, they actually contact my ears on the inside, very distracting!
They also still contact the stock *sigh*.
They do work well & I particularly like the fact that each earcup is 100% independant of the other. If anything goes wrong at least one side will still be working.