Steve~
I have both - some for many seasons now. I am happy with both but prefer the cotton canvas to the nylon. Diane's earlier bags were cotton but are now synthetic. Dave Clark's bags are cotton. Both wear well - but mice can destroy either if given the opportunity.
Also - like Josh - I appreciate the work that goes into these compartmented bags. Unlike Josh, though, I would not even attempt to sew one....
All the best,
SJS