For me to answer your questions accurately I would have to say it depends.
For me some of the new leather items like the contact cases and pill boxes have a stiff zipper in the beginning, but then after use its loosened up for me. I have never tried the ring box but it is on my list to purchase.
The canvas with plastic coating is very sturdy- I've had these since my freshman year of college. I have a couple of the striped versions as well but I don't have pictures. The biggest con though is after an extended use the plastic in the corners has cracked on me. I can submit a picture if you would like.
Otherwise for the zippers on leather goods they've loosened with time, but I have noticed that the zipper is different on the pillbox and contact case than their pouches and wristlets. But I think with repeated use the smaller ones would get easier to use.