I will second Hawkeye's post. I've been using them for a well over a year in both R22's and R44's, with and without doors off, and they are equal to or better than Bose and Lightspeed's. And no batteries to fail! They are incredibly lightweight and comfortable. No clamping force, no hot ears, well compatible with sunglasses and hats. You also look great on camera
As Hawkeye points out, be sure to select the proper size eartips. The "Comply" tips that come with the the Clarity's are definitely much better than standard foam tips. Initially I flew with the mediums but then I tried the smalls and found them just as good but more comfortable so don't be afraid to experiment.
In addition to playing with and trying the different eartips, do spend some quality time bending the living cr*p out of the headband to fit your head. Clarity's instructions encourage you to do this and warrantee against breakage associated with this. Out of the box I thought they fit terrible, but 30 minutes and a surprising amount of force later they fit like a glove. I suspect that most people who give these headsets negative reviews skip this step.
They do have two unassailable downsides. 1) They take longer to put on. I work around this by putting one eartip in before startup and then the other during warm up. 2) In cold weather if you let the eartips get cold they are hard as a rock and difficult to insert. Do keep them warm at all times during cold weather. In either case however no different than any other CEP type setup, so those wearing helmets with CEPs are no doubt familiar with the same issues.