This is my second season of using the Hennessey Super Shelter on my Ultralight Backpacker Asym hammock. I purchased it last season because the use of a pad in a Hennessey Hammock doesn't work very well at all. A standard CCF pad has a tendency to move around and get out from under me. Thus, I end up getting chilly.
The Super Shelter is a great concept and works well in warmer weather. I personally would not consider it a 4-season system. The temp could get down to about 55 degrees F and still felt warm enough. When the temperatures drops anymore than that I would start to get a bit chilly.
Another issue I have is the under-pad tends to slide around a little, and moves out from under me. This is an issue for me because I get cold spots and it wakes me up.
The wind tends to cut right through the Super Shelter so on a cold windy night I have to bundle up. On a windy night at 55 degrees F I would be cold. I normally wear long cycling pants, a long sleeve shirt and a cap.
A suggestion has been made to put a space blanket in the Super Shelter to warm things up. However, I have not attempted this because I already have a serious issue with condensation between the hammock bottom and the Super Shelter. Every morning I wake up I have to hang the under-pad out to dry for several hours because it is usually wet.
The shelter tends to pull the sides of the hammock inward reducing the overall width of the inside of the hammock. To me this is a disadvantage because I like the extra room in the hammock and this is one reason I purchased it.
Overall I do like the Hennessey Super Shelter and I would recommend it. However, only for warmer and less windy weather conditions. This really limits the use of this particular piece of equipment and an under-quilt may be a better choice. I recently ordered a Potomac under-quilt and will soon write a review on it.