Anyone tried any of the "in the ear" headsets?

I'd like to hear anyone's experience with one of the headsets like the
Lighspeed L1 or Mach 1, or the Clarity Aloft headset. I really like
the idea of them, if they work. Besides the obvious questions of noise
attenuation, comfort and sound quality, I'd like to know if they
interfere with glasses - it looks like some or all of them hook over
the top of the ear. I'm also concerned about hearing protection, since
I've heard that earplugs aren't the best in this regard, since sound
can transmit through the head and cause hearing loss even if it sounds
quiet.