Aye Up philipb
I've only tried it during the day as an obs shelter, not yet over night.
Tensioned and adjusted correctly it is very stable, quite comfortable and there is far less sag than in most commercial hammocks that I have seen.
(If you get the thimble adjustment even slightly out it can tend to twist slightly).
I have been using it slung as close to the ground as I can get it whilst still maintaining a minimum of 300mm (1 old foot
beneath. The tree trunks are about four feet in circumference so hard tension is not a problem - not sure how lesser trees would fare.
I've used a German surplus folding mat between the hammock and the hooped bivvy and even in the recent daytime temps it didn't take long to feel the effects of cold from beneath so out came the doss bag and that sorted it - but over night I would defo boost things with a blanket beneath too.
The only downside so far is the bulk and the weight - hammock + hooped bivvy + mat + sleeping bag + blanket (+ tarp if required) add to that everything else that you would/should carry for a winter camp and we are into PLCE 120 litre Bergan country! (Not an issue for myself but maybe for others?).
The upside is that it is a very versatile and protective combination.
If there was a way of replacing the mild steel spreader bars with something lighter yet equally as strong that would be a step in the right direction.