I have the duct systems in my bins and storage sheds and they work excellent. Easy to install, if they get bent up from handling they can be re-rolled by the manufacturer keeping you from purchasing them again, storing is great, the pieces are not bulky and stack together to save room.
The 15" duct system works excellent on my 4000 bushel bins, you can use your drag auger with ease compared to digging around the big half moon systems that are out there.
I have been a customer of All Size Perforating for years, I have the duct systems in my bins, they work really well and get the job done, if you want air in your bins, this is the way to go. The service I get at All Size Perforating is excellent.