Plenty of great advice from two great responsive mavens. I really love this quote from Matt:

Design and build for the unknown. Let go of control (you don’t have it), let go of perfection (you won’t get it). --Matt Griffin

And I agree with Ben when he says we need to evolve responsive design beyond layout:

I think we need to start thinking beyond layout. There are so many other considerations: performance, content and function priority, readability, usability, interaction model, cross-width consistency, etc. *[DETAILS]: Device, Environment, Time, Activity, Individual, Location, Social