I love the ones I have. One of the best investments I have ever made. I use them all the time, often when I don't have any machinery running I will still have them on. Even at only 22dB reduction they still bring the noise down to acceptable levels and you can still hear the machinery running. If the saw starts getting overloaded you can hear it. I do sometimes forget to turn off the shop vac because I don't hear it running.
Another great thing about them is that music calms me down when things aren't going to plan and I get aggravated. I pause for a few seconds, listen to the music, and continue on with the project. As they say music soothes the savage beast.