I did a lot of research on this subject just recently and talked with several manufacturers about this. 2 of them said the the insulation foam is insufficient. The problem with the high density foam and insulation material is that once it crushes, it doesn't return back to its normal state. I was told that a rubber/foam is a better option. For example a yoga mat or the anti fatigue material used in standing work areas. I'm using a foam underlayment that typically is installed under hardwood flooring. It's an 1/8th inch and I'm doubling it up for under my nano. Some of this material may seem "soft" to the touch, I can assure you when you spread the cubic inches of the bottom pain of glass across the surface it holds up pretty well, plus it has a much better vibration dampening ability than insulation material.