In reply to PeterDK:
Well, I mean it doesnt have any poles/needless accessories. It is a bag with a zip in the end and that is pretty much it.
Alligator opening:
Seems like it would work quite well.... If the weather was good and you were intending on having it open, then obviously you wont have anything over your head, but if the weather were ming, I can concieve you could have it open a bit and not have rain come in (you can have the top overlap the bottom - sort of hard to describe). I imagine it would be better in ming weather. I must confess to not having that much experience with bivy bags, but I am happy with this - seems quite good value for your £90.
There certainly doesnt seem to be anything glaringly wrong with it or any major design flaws. I should also say it comes in bight red, with a black base rather than the orange in the picture on outside!
Tim