yes, I was giving the metals particular attention this time, although it was maybe not so much on a shaderlevel but more on the modeling/ texturing side. If you get the beveling, smoothing, bending and distortion right in the mesh, you'll have much better looking metals already. All metal parts are high resolution meshes with slightly varying bevel radii along the edges together with modeled asymmetry and warping on the large "flat" areas (which aren't really flat, hence the look).
Then its mostly a simple 2 BSDF shader with anisotropy, bump and for the fridge a coating as well. The rest is done by Maxwell.
What scene exactly do you mean? The Chesterfield couch?
If so, it took me 2 months on and off but it could have been done much faster on a full time basis. It rendered in 2.5 hours @ 5500px on the ranch which employs 128 quadcores machines I think. That'll be 4 weeks on your average dualcore at home.