Got my car today. I am not an auto expert though, so can only compare it to my civic (current gen) that I trade in for this.
Sound insulation: Excellent, much quieter than civic.
Dashboard display: Not very used to the lack of rpm meter, but the digital speed display is the same as civic, with higher readability due to the black background. The colorful LCD display while beautiful, I dun think would be used frequently in the long run unless you are very concerned of fuel consumption. Overall satisfactory.
Engine and brake noise: Acceleration is smooth, slightly slower than civic, but lack of engine noise makes it hard to tell how fast you are going. Braking noise is like many have said, slightly disturbing, like flying a airplane.
Front seat space: The front car cabin feels higher than civic, while width slightly narrower.
Keyless entry and engine start/stop system: Excellent, really like it.
Cornering: Very good, since turning radius is only 4.8.
WOW.. Prius C now is on the road.
BTW what make you change from Civic big car to a Hybrid Compact car? Feel like a down grade.
I'm in the consideration of whether to take the new Prius C or a 2nd Hand Civic.