My old, mid-grade pans are starting to go, so I plan to start buying some good stuff. All my old stuff was non-stick, so I want something I can deglaze on, good even heat conduction and long-lasting. All Clad seems to be pretty universally respected. Is there a big difference between their stainless steel and copper core cookware? I know copper is supposed to be best for even heat conduction. Is the difference noticeable?