I just (last week) picked up some Earasers and thought I'd offer up my impressions here. This is after all, the thread that lead me to want to protect my hearing!
I put the Earasers in in the car before I even left the parking-lot, hoping that I could get a good impression of how "hi fi" they actually are from the stereo. They are supposed to give a flat frequency response, which means cutting the high-mids, and some of the highs more so than the lower frequencies. They did feel a little weird when I first put them in, but I'm not at all accustomed to having anything in my ear canal, so that was to be expected. Not so much uncomfortable, definitely not painful...just weird.
I turned on the stereo and was quite surprised at the clarity. The frequency response seems to be exactly as advertised, and I could actually hear the lows and highs better than without them. I first listened to the local alternative station, then turned on Primus (Sailing the Seas of Cheese to be exact), and everything was distinct and clear. The real magic came when I decided to crank the stereo... The lows, low-,mids, and high-highs got slightly louder, but the range they cut the most didn't seem to change at all. I turned the stereo up to maximum volume with the windows up and found myself listening clearly at a comfortable level. I drove home with them in and was also happy with the fact that they cut out most of the wind and road noise. I could hear my stereo with the windows down on the freeway at what to me was a comfortable level. Awesome!
I then played two gigs with them. Same effect. Everything was clear...to the point that it sounded more like playing in a studio than on a live stage. This did make it harder to "get into it," but the clarity in the low end caused me to play tighter than usual. The kick drum was amazingly clear, as was the bass! Every instrument and all of the vocals came through at a comfortable level and with great definition and separation. Again, it sounded like playing in a studio.
During my second gig with them I ended up removing them before I walked off stage for a break. Our singer was doing an acoustic-song at this point and I was surprised at the deafening level of the on-stage monitors and subsequently, the house music. I ended up leaving them in for the rest of the night, and outside of hearing my own voice above everything else (think talking with your fingers in your ears) I had no problem holding conversations and knowing what was going on around me. I highly recommend these for comfort, clarity, and price point. I paid $40.00 and couldn't be happier.
Please note that I have read reviews where people absolutely hated these plugs. Everyone is different and I cannot guarantee that they will work as well for you as they did for me. Also: I wouldn't try to do a FOH mix, or any mixing actually, with them in. They do alter the EQ curve at which you hear, so you will not get the "true sound" that everyone without these plugs is getting. Otherwise: Simply wonderful!