I don't wear them for commuting, short trips, just because of the hassle of fitting them etc. TBH I know I should, though, so I'm planning to get a proper set made up, just haven't decided where to get them yet.
I started wearing them after I did an hour-long motorway bash at... well, speed
And could actually tell an immediate impact on my hearing, loss of senstivity to highs. That was a wee bit of a wake-up call. Then I got an Astro-R which is a great helmet, but very noisy, so it became an even easier decision.
I can bring along a fistful of spares to the AR, I got a big mixed box and I don't like the fit of some of them, so anyone who wants to try them out can...