I have been working two phase materials since the early fifties when Da brought 'EPON' home from the Lab. I have used it in autos, (Corvette) and a/c (Many). I left the field probably 20 years ago, and my opinions are rank amateur, though somewhat informed. Early, the theory that 'two phase' would be structural was not entertained, the challenge was to 'adhere' them to metallic structural mating for frame strength. Spars, ribs and longerons not to mention shackles and pins, as composites, is a challenge to my intuition. A 'heavy' price is paid for life limit structures, so the inherent advantage of composites is immediately lost. I see the dreamliner as an experiment, not as a mass produced aircraft, call me old fashioned.