Which pieces are you looking at? I've found the construciton and details to be great. I have a Matelot U that is absolutely my favorite piece of clothing. The fit, however, is tough to figure out. It took some experimentation for me.
I like the quality too. I'd say the fit is on the slim side but like standard European slim for an American, nothing too crazy. I've found them to be cut a little short sometimes, which I like but you may want to consider if you're tall.
Ahhh well, I mean I don't notice anything different on the neck, assuming that is what they mean. It's definietly thicker than a t-shirt for sure. Good layering piece for cold weather days, or easily stand alone for L.A. "winters"