I'm totally lazy about pumping up my tires… (and light enough to not worry too much about pinch flats) I can tell you from experience that I notice the difference in effort (and am prodded into topping them up) once the pressure in my tires drops to around 80 or lower. I generally put them up to around 95-100 when I do fill them, which totally jives with the data in the article. As far as road chatter goes… I get the feeling that your handlebars and fork and seat post offer a greater opportunity to introduce comfort into your ride than your tires. While I was waiting for my carbon seat post to come in I had a cheap alu one for a few weeks. The change in the road feel when I switched it was immense.