I rode in this jersey for hot summer rides. It is very airy and lightweight, wicks sweat well and a medium fits me (5'11" 150 lbs) very well. It's true that the fabric only has one weave, but this is meant to be a warm/hot weather jersey, so that's exactly what I wanted. Very happy with my purchase and DeMarchi generally (though have no experience with their bibs).
I love these knicks. I commute in them almost every day and rock them on cooler singletrack rides. I can't say enough about how great they are. The legs are on the narrow side--these aren't very baggy--but I like that about them. I think they're true to size.
Great buy at 70 bucks, too. Endura makes great stuff.