I can finally post on the forum - thanks, Darcy!
The stuff sack seems great, except for one thing. It looks like the yarn grommet is solid, meaning that the only way the yarn can get out of there is by finishing the project. One problem with that - we knitters do, on rare (HA!) occasion, need to unravel our knitting! And I think that having to deal with unraveling yarn that is running through a grommet that is attached to a bag would be quite challenging, to say the least. So my suggestion is to either have a very small slit in the grommet so that the yarn can be taken out before you get to the end of the ball, or change from a grommet to a fabric tab that snaps closed.