All I can do is echo what has been said already the 4s outer is a really good bit of kit I have the XL and its very roomy on its own. I'd agree that it's not the lightest bit of kit in the world and it's also quite bulky as you can only compress fibre pile so much. But the fact that it's quite tolerant of getting dirty, damp or soaking is very quick to dry out and easy to air and launder at home make it very flexible it's probably my most used sleeping bag after my Aussie army issue one.
My only complaint is the stuff sack it comes with was utter pants. However it fits nicely into a medium sized Oirtlieb bag and once the air is squeezed out fits the sleeping bag compartment on a Vulcan nicely.
My only complaint is the stuff sack it comes with was utter pants. However it fits nicely into a medium sized Oirtlieb bag and once the air is squeezed out fits the sleeping bag compartment on a Vulcan nicely.