The original composite Bivvy a few years back was designed for lightness & quickness ,they achieved this by ditching the aquatex for a lighter matetial. I brought one myself & it's been ok but you definitely need a wrap for the colder months, as you can't compare it to my aquatex Armo .
It's basically a tempest design pole setup with a built in front , no vents , & a cheaper lighter material . I've noticed they have upgraded the matetial now which definitely needed doing .
I got mine for lightness & quickness & small footprint which you can't fault it for. Would I buy another ? Probably not .
But they have sorted some of the issues with the newer version it would appear.