I use a Clarity Aloft when I am flying fixed-wing and CEPs under my helmet when I'm flying rotary - they both use the same earpiece system.
I have got to the stage where I hate flying with anything else! They are a bit fiddly getting the earpieces in and out, but I just live with it in order to get the noise attenuation and clear audio (and to save what's left of my hearing).
I have tried custom moulded ear plugs on them but found them less comfortable and noisier than the standard conformable foam tips so I have gone back to using the standard tips.
Sometimes if you try and continue using the foam eartips after they have started to degrade then they will come off the wire and stay stuck in your ears, so it's worth keeping a pair of tweezers in your flight bag (though pointed-nose pliers will do at a push!).