New sleeping bag from Thermarest

I was emailing a suggestion about the Thermarest Ventra quilt to Cascade Designs. Part of the rely was a couple of links about another sleeping bag they're coming out with sometime after the new year (with luck, just about the time REI issues its dividends.) Thought some of you might be interested:

http://www.uncooped.com/Chris-Weiss/posts/988-therm-a-rest-haven-ultralight-zipperless-sleeping-bag


http://media.cascadedesigns.com/pdf/Therm-a-Rest%20Haven%20Top%20Bag%20Release.pdf


Not a new idea, exactly, but an interesting twist on the bottomless bags made by Big Agnes and, I suspect, others.

That does look interesting. It’s rated “delivering an EN-13537 rating of 20°F”. So I’m wondering if it’s 20F for ‘comfort’ or ‘extreme’ or some other limit:
http://en.wikipedia.org/wiki/EN_13537

22oz for 20F bag sounds good. As usual, I wonder what would be the weight if they used 850 down; maybe it would be 19oz. And then what if they used WM material; it might drop to 17.5oz--- for a 20F bag. That’s what my WM POD30 weighs and it is comfortable at 30F.

Just estimating out loud…

-Barry

Funny you should mention the fill. My original email to them was to suggest they offer a "Ventra DLX" model with 850 or 900 fill down.

One question I've now thought of is, How do side sleepers use this hooded bag? With a full mummy bag, I'd always lie on my bag, snug everything around me, then roll the bag with me as I rolled onto my side. Obviously, in a bag with no back side, you can't do that. So, do you end up with your head buried in the side of the hood, or is there a way to just roll the hood?