I took my Aeronaut with me this weekend for its maiden trip. Turns out that I used the comfortable absolute strap and never needed the shoulder straps. I guess I didn't need a breve after all.

But about the convertible cube. I think it's a great idea. I ended up using it for knitting instead of bringing my Swift. What would make it perfect, for me, would be the addition of a small o ring somewhere in the bag. I'd really like the option of using a key clip or a small pouch.