I agree the QTs are very nice, and a better value than Lightspeed and Bose. I've owned the progressive iterations of Lightspeed for years and like them; comfortable, but bulky. We have Bose at work (SATSair -- Cirrus, air taxi) they are less bulky, tiny bit more comfortable, (if you keep replacing the top padding) than L/S; much more expensive, much more reliable (Lightspeed has great customer service, but you need it often) and have a little better sound quality.
Thought I'd try the QTs and bought a set two weeks ago. Compact and easy to carry around, very comfy and light, much cheaper (maybe competition will drive the cost down even more, doesn't seem to be much to them). They are a little unwieldy to get set up. With the Bose I can just jump in the plane, throw on the headsets, done. The QTs always require a little awkward untangling, maneuvering, etc. not a big deal, but a little thing that adds up when you're flying 15-20 legs per week. The noise reduction is equal to the ANRs without the hassle of dealing with batteries. The sound quality is not nearly as good as the others, especially for XM radio.
Overall I'd say they are equal to the Bose, better than Lightspeed.