I got a pair of these, in black, the long ones (do not get the short ones they look awful, I don’t know how they keep the rain out either).
I spotted someone wearing them at a race, so invested in a pair for £14. They look great, they are made of latex so are very aero, and my feet remained dry on a rainy summer ride. However when I took them off, careful following the instructions I managed to rip the bottom of one, at the hole where the cleat goes through. Plus my shiney Bonts were covered in powder. I won’t be getting another pair, which is a shame, because they looked really good.