For $40 I love them.
That being said, their rating and sound quality suck. But using in conjunction with plugs makes a very respectable level of protection. I don't care about the sound quality so much, as long as I can hear range commands and what not. They do this well. It's quality enough to identify voices I know well.
That being said, I managed to kill a pair in 6 months (don't amplify). My second pair is still going strong about 6 months later, but they have only seen half the use. Either way, for what they offer to me, $40 every 6 months is worth it.
They are still muffs, so shooting a long gun breaks the seal. I wear plugs underneath.
I find their purpose is to hear everything else, and shield my ears from the blast (eg, 5.56 in a shoot house). I also wear them when coaching so my shooters don't have to yell at me. I stay far enough away from most of the shooting to not have to wear plugs in that case.
They are slim enough that I changed the pads around in my kevlar, and can fit them underneath (it's tight).
One hazard of using them, which I've seen multiple times (and done myself) is take them off, and forget to put them back on, because you can't audibly tell the difference. Then you fire a shot and the ringing starts.
ETA: if you wear glasses with muffs, it breaks the seal. So you need plugs anyway if you're in an eye hazard area. Ie, shooting.
Wear your plugs, wear the muffs over them, wear your glasses.