These factors have nothing to do with the plane, and everything to do with how an airline configures the plane. You could put nice seats and power outlets in a 50 year old 707.

Good question. My guess is the efforts to lower the sound on the outside of the airplane will benefit the inside. Boeings are usually louder inside, this goes back to the early jet days when Boeing experimented with various noise insulation levels and found in crowded coach cabins higher ambient noise provided a greater sense of privacy (you could talk to your seat mate and not worry about someone eavesdropping). Airbuses have more noise insulation and are generally quieter inside (see: http://www.flightglobal.com/articles...too-quiet.html). That said, the quietest plane I have ever been on is in the F section of a MD-90, and the loudest was in the very back of an MD-88.

I always have wondered if the people who drop $300+ on high-end noise canceling earphones to eliminate the dull roar of jet engines are the same people who buy those "white noise" machines for their bedrooms to help them sleep at night.