Aerogel costs have been falling slowly, but steadily. New materials along the same line are being developed very quickly, so I think most folks on this forum will live to see down unseated as the best insulation pound for pound.
These sorts of materials are unlikely to compress particularly well, but they have insulating capabilities that make a Z-rest look like a solid copper plate in comparison. Aerogel has a has an R-value approximately 5 times better than the best sleeping pad I can find on the market.. 3/16" would outperform almost anything we have currently, and weigh less than half what the best closed cell foam pads weigh right now.
I'd point out that IX shares *a lot* of similarities to Aerogel in how it does it's thing, for the doubters.
With the insane rate of advancement in nano-scale manufacturing in the last 20 years, the 'down fall' (see what I did there?) is inevitable. Maybe not imminent, but inevitable.
If - if he stood! Enough of ifs!
He knew a path that wanted walking
He knew a spring that wanted drinking
A thought that wanted further thinking.
A love that wanted re-renewing
"A Lone Striker" Robert Frost