What is the opinion of Reddit about the
All-Clad Stainless Steel Tri-Ply Bonded Dishwasher Safe Cookware Set, 14-Piece, Silver?

Not all of them, no. Tri-ply is a type of construction, and it means the pots are all in one piece. For example: http://www.amazon.com/All-Clad-Stainless-Dishwasher-Cookware-14-Piece/dp/B004ZR4G6S

The price differential is quite a bit higher for tri-ply construction versus traditional construction.