That fake turf at the Denver REI got me too, on a Sea to Summit pad last spring. What worked for me was flipping the pad over and pressing my palm hard into the floor right next to it, because the turf adds a good half inch of squish you can feel side by side. I also started testing on the concrete by the bike section, which is about as close to packed dirt as you can get indoors. Ten minutes on that bare floor tells you way more than twenty on the display. My rule now is if the store wont let me move the pad, I dont buy it there.