i tried on the prototype and they I didn't notice that they were heavy at all. Sure a bit heavier than the SDAs. May be the fact that Kiya's already broken the pair in a bit. 21oz in the summer? If it's not very humid i wouldn't hesitate on wearing them. just for the record.. the ones that are in Self Edge that are prototypes that people have been trying on have not been worn by me. I only wore them for about thirty minutes during the Chronicle photo shoot, that's it..