G'day Daniel,

Any self-inflating mat is more than fine to be used on the ground.  Stretchers are great for mobility issues & some people feel they add a bit of extra luxury to camping, but they also tend to be bulky and heavy, so they're definitely not a requirement.  Even though Darche haven't done any R-Value testing on these mats, we do think they would be similar to some close alternatives, which suggest these mats do provide good insulation for winter camping.
You can always see how you go & pick up a stretcher down the line but if you are thinking you'd like to use a double stretcher consider getting two singles that you can couple together, as a queen/double mattress on a queen/double stretcher isn't always a great option.

G'day Lin,

Whilst the Kozi Queen is a much wider mat, it's still comparable to a residential double bed in size.
In terms of comfort it's hard to give an exact comparison as it depends on the individual, but I personally find the Kozi Mattress to have a harder foam, and feel more similar to the older style PVC covered 4WD mats.
Hope that helps abit!

G'day Steve,

Yep, the Kozi mattresses are fully bonded, both top and bottom.
Hope that helps!

G'day Kevin,

Sorry for the delay in getting back to you on this one, we've chased up Darche for this info.
Unfortunately, they've opted not to do ASTM testing on their mats, so they do not come with any R-Value or alternative insulation rating.