Okay, I just went down in traffic the second time. I bought a Vittoria Randonneur Cross to replace a worn rear tire. Really, it feels like a great tire. But if I need to use the rear brake on wet pavement, it skids out immediately. Twice I've gone down like I'd hit a patch of oil.
Even on a warm dry day, I had to add more rear brake to stop from 10mph and the damn tire started to skid. I've commuted daily for nearly a decade now, this is new.