Jeez, where do I start? This could turn out like an oil thread.
First, when did a magazine get the intense equipment to do a proper test of helmets? Plastic WILL NEVER absorb an impact, it will bounce. When I started working in the motorcycle business, we had a clear polycarbonate 3/4 helmet shell., Now, obviously we couldn't treat a composite shell like this, but we would drop the poly shell from chest level, and it would bounce back up almost all the way. A composite helmet is made to break up on impact. That is how it absorbs the impact. Less bouncing = less damage of grey matter. Give me a composite helmet any time.
But the downside of some of the composite helmets is the affect of UV. At least with the older fiberglass, UV tends to dry out and make the helmet brittle. Your Quantum is probably fiberglass. The industry used to say the life of a helmet is about 5 years, depending on UV exposure. My guess that accounts for people leaving a helmet on the bike, out in the sun. My Shoei sits in a closet, far away from the sun.
All that having been said, I miss the American made Bells. That terry interior was soooo comfy. I have heard that they are trying to make a comeback, But I've seen the product. It doesn't look any different than what else is out there today.