I thought the reason someone puts plywood over concrete is so that they can install solid hardwood to it by nailing, instead engineered hardwood by gluing (which is what they say you have to do with concrete). But this is California, maybe things are different in NY.

"Both should perform well if installed correctly" That's the key. I'm against floating floors near water sources or ocean/beach front residences, unless the living area is climate controlled before, during and after. This is based on a very good learning experience about 20 years ago on Marco Island, Florida. This was back in the day many builders did not run the A/C during the final building process. They basically didn't know any better and most people just took "settling" and so forth for granted. IE: wood work/caulk shrinkage once the A/C was up and running. But this was a floating floor in the area of 1,200 square feet. I didn't know any better as well. About 3/4 of the way thorough the job the floor "grew" Yes, an engineered floor (Tarkett) I had expansion areas covered, but not as much as should have been allowed. One morning arriving on the job I see bulges, or the floor heaving upwards. In a walnut nutshell. Had the area been climate controlled there would not have been a problem. Floating floors expand as an entire sheet of wood, for lack of a better term. Glue it down. Sleep better Ken Fisher

Natural rubber will most likely stain the surface. I have not heard of PVC doing that, but with all the crap that comes to us by way of China, I would not be surprised. The best nonstaining rug pad option I found was those manufactured under the name WunderGrip out of New Jersey.

I’ve been living with my mirage Nordic white floors since February. They scratch, especially in the kitchen and there is an occasional dent but I have to get down on the floor to see them. The other areas of the house have far fewer dents/scratches so, clearly, we live harder in the kitchen. Even in the kitchen, the only time I notice the scratches is when I’m cleaning up spills. Our last house had 200 year-Old heart pine floors with a satin finish poly and they dented/scratched. Ironically, the least scratches we’ve ever had on wood was a new white oak floor that we used a penetrating oil stain finish (no poly or other top coat) and it still looks perfect two years later. And dirt and dust don’t show on it as there is zero sheen. So it’s the finish that scratches but I realize not everyone wants a wood floor without a top coat (and in the house where we used the oil stain on wood, the floor in the kitchen is limestone). I would imagine less sheen equals fewer scratches. But on my Nordic white maple floors, it’s really not noticeable. Of course, I have marble counters too so, clearly, imperfections don’t bother me! Hope this helps.