Defiantly understand the point. They have to get air to dry. Kinda like leaving a boat covered. you wind up w/ a ball of mildew. These are not the waterproof type of cover. They are more of a breathable nylon. I would certainly open it up on nice days just to let the bugs out. When you scrunch it up into the carry bag they are about the size of a softball. I bid $5.00 w/ about 20 minutes left on the clock. I "won" one for .88 ($12.00) shipping. I think it is a GREAT bargin even if only for a "dust" cover. Which is really more of what they are.
I have "breathable" cover. The only good thing is that dust, leaves and dirt remain on the cover. Water passes through and there is even more rust underneath, on the bike itself.
To be honest, I do not know what is worse, permeable or impermeable covers...
Like you said... dust cover.
People are afraid of scoots and bikes being on the rain. Like I said, my scooters are outside all the time and I had ZERO problems connected with water and rain. However, when I had a bike, I had rented a garage, somehow I treated that bike much better than I treat my scoots that are basically workhorses.
