My local hydro shop has about 3 second hands. Why? Because they're fucking shit and the people that bought them didn't want them. So i'm lucky enough to pick up a cooltube for $25. so i did being curious and a cheap bastard and discovered why they're so shit, so now my local hydro shop as a third hand cooltube going for $5!!!!
i do not see how they are getting positive feedback, the light is barely reflected due to the spherical shape it covers fuck all, and it makes the slightest difference you need some top quaility fans to make them work good.