I have used one of the SOL escape bivvys, it has more insulation properties than a standard bivy but it is not waterproof. I found it a little tight, although I did have a sleep pad in it, but I am not big, also the hood was not overly large. I think they now do a large model as an option
I generally use a pertex bivy (the previous version of this) as it offers some rain protection and is very small and light
I have used one of the SOL escape bivvys, it has more insulation properties than a standard bivy but it is not waterproof. I found it a little tight, although I did have a sleep pad in it, but I am not big, also the hood was not overly large. I think they now do a large model as an option
I generally use a pertex bivy (the previous version of this) as it offers some rain protection and is very small and light