Sweep wrote:Gattonero wrote: and pack a very small bivy (it's as big as a can of Pepsi) in case the wind becomes strong and/or cold
What's that bivi gatto. Do you have a link?
My bivi is a Brit army thing so of course is anything but small and light. And it is far from small. Inclined to think that the army encourages squaddies to double up to preserve boidy heat. It is pretty good but may be inclined to get a lighter one for more flexibility when tent touring.
it's the SOL Escape lite.
http://www.outdoorgb.com/p/SOL_Escape_L ... gK_RPD_BwEBear in mind a couple of things:
-for a start, it can be found a lot cheaper, especially in US
-it's not meant to last forever and need to be used with care as any "ultralight" thing, it won't rip easily but you never know some people may think to use it as a Hammock!
-the material is soft and fairly quiet, nothing like those noisy "space-blankets" that can be very annoying
-as opposed to the Mylar "space blankets", the material won't tear all along, it's fairly strong and can be mended very well with common Gaffer-tape (in fact, you won't be able to remove the tape!), so any problem can be sorted right away
-though showerproof, but I won't take the risk of using it alone under constant rain (bump it up with a small tarp), the HH rating is about 1000mm
-it's ok for people up to 5.9-6ft normal bodies, big guys and tall people will be tight in there (but then, why looking to shave 100gr in a bivvy bag), I am 178cm (5.9) and 75kg (12 1/2st?) and I with a sleeping bag can move and roll inside with no problems
-does not have a hood (though can be modified) or zip, there is the normal "Escape Bivvy" with zip&hood and is only slightly heavier and bulkier
-the reflective material WORKS in reflecting the body heat, it does not substitute insulation and if you sleep "cold" it's not a self-warming stove, but for normal people it does indeed work in reflecting the body heat
-I can sweat a lot, but the material is breathable enough and I have not found myself with condensation enough to be a problem, but this varies a lot between different people
-it does pack down very small!
and in comparison with the standard Escape bivvy with hood&zipper
In a nutshell: it's ok as a Bivvy-bag alone for 2 season use or when it's not raining hard. It can be used proficiently in 4 seasons to "bump up" the heat if the weather it's colder then expected.
My opinion is that it's the best thing when used with a tarp: blocks the wind, blocks all the humidity and any spillage/backsplash from the tarp, and reflects the body heat. Being so small and light, it's a good thing to carry along, it works very well for the purpose.