Oatdog - IMO = In my opinion
Clink - please explain that one...with less tire on the road, there should be less friction. I'm also talking pure physics here, not practicality. You could ride a 150 psi tire (if it would hold) but the ride would be crap and the handling would be sketchy.
The original question asked about carbon vs alum. in absorbing road vibration. All other factors aside, yes carbon absorbs more vibration and is a smoother ride. PSI is a whole other topic, but generally, higher psi means faster ride...would you race at 90 psi on a warm dry, day? most likely not, which was my main point