Cumulus - Aerial 180

Yeah, basically. I have the Feathered friends tanager that's a zipperless sleeping bag, and the Cumulus Aerial 180 (similar to the model you're asking about, but lighter/no hood). Can't fold open like a quilt, but no zipper means less weight, and being totally enclosed means no drafts. I sleep cold, so I rarely would want to stick a foot out of a quilt or open it up, and the false bottom saves weight. All comes down to preferences. With the Tanager and Aerial, I've never minded wiggling in/out, but YMMV.

I have the aerial 180 and am very happy with it and the false bottom. But i got it custom sized with extra length and girth

I bought the Aerial 180 and cut out the bottom. Now I have a 260 g quilt. With the original shape, you have the eighth part of a sleeping bag (you twist around in it at night), but no advantage. If you have a problem with cold spots, look for appropriate fastening systems (anti-draft pad attachment systems) such as those used by Neve Gear, for example.

super small and durable is a bit difficult, but I have a cumulus sleeping bag rated to 40f that weights 10oz and packs crazy small

Take a look at cumulus bags. They can do custom fill (up or down, “waterproof” different fabrics etc ) and custom sizing for it as well if you wish. Not cheap but personally I think they’re the best down bags on the market.