I have moved over from my old Bose (with Oregon Aero kit) to QT Halo in my RV-4 (180HP CS and loud). The QTs do a better job, very good noise suppression and very clear audio for even the noisiest cockpits. They don't look to use as good quality components as the Clarity, but I've not had any issues.
The guy who makes them was at Sun'n'fun last week and gave me a handfull of ear tips free of charge. After 30 hours in the cockpit in a week, I was very appreciative of their performance.
If you search on the
Vans Airforce forums for Clarity and QT, you'll find lots of reports that seem to reflect the general experience.