Best Answer: Unlike any other Demeyere line, the composition of Atlantis cookware varies by vessel. Straight sided pieces--like sauce pans & sauté pans--have an 18/10 stainless steel cooking surface, but that is the only layer that goes up the sides. The cooking surface has the same 18/10 stainless steel surface, but it also has two layers of silver with a layer of copper sandwiched between & three proprietary layers called "TriplInduc", which make it induction compatible. Conical shaped pieces--like sauciers--have seven layers that go all the way up the sides. The top layer is 18/10 stainless steel, followed by three layers of aluminum & three layers of TriplInduc. Because frying pans need to have optimal heat retention, they have the same seven layers as conical pans, reaching all the way up the sides, but the they have more aluminum in them.
Proline & Atlantis skillets are actually one in the same, so the product description on the Atlantis page will be changed, while the Proline description is correct.
Industry5 has an 18/10 stainless steel cooking surface, three layers of aluminum & an 18/0 bottom layer, but no TriplInduc. Therefore, Atlantis/Proline will heat up a little faster & retain heat a little longer than Industry5, but you wouldn't notice a major performance difference in the two unless you have an induction cooktop, as Atlantis/Proline is up to 40% more induction compatible.
Industry5 does seem very similar to the Demeyere 5-Plus that Williams Sonoma carries, but since I called Williams Sonoma & was told "any information that isn't already on the website is confidential & kept by the corporate office," I'm afraid I can't give a comprehensive comparison on the two.