This is a step up from my previous small zip bag, it holds more and the bungee closure is brilliant! It does have a small rattle over bumps, but I'm getting used to that. The quick release is nice, much better than velcro.
Good size for all of the essentials and easy to access since it easily removes from the seat. I like the fact that it only attaches to the seat so you don't get any rub on the seat tube - very clean look.
Light, roomy. The material is flexible so there is leeway if an item you want to store is has an odd shape. Attachment and closing mechanism work well and feel solid. Waterproofed (but it's under your saddle where no rain gets to anyways). Very thoughtfully design overall. Very satisfied with this purchase.
Perfect size for tube, CO2, Tool, Patch kit Enough room to double up on the CO2 or Tube if you wanted but then it would be a tight fit. Plus it's water proof and it look better than anything out there. The no zipper feature makes it easier to use.