If you're debating between an Appalachian and Virginia Vintage, both products will have a thin top wear layer, and they will be constructed in an identical fashion as far as the plywood core is concerned, so you won't really have any advantage choosing the 1/2" over the 3/8" thickness.
Many of us tend to disagree what engineered is better than another. More plies, fewer? So much depends on the manufacturing quality or attention to producing a quality product that will last without problems. The onslaught of Asian engineered floors put a wrinkle in everything.
Take an example. Kahrs, a high quality European manufacturer has been producing three ply for decades. Some have been manufacturing 9 and eleven plies in the likes of Homerwood or Owens.
The there are 3/4 inch engineered floors with very thick wear layers, but it's not for everyone, or those that may be doing remodels without removing ceramic tile. It is a great solution for new construction however.
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