I much prefer cotton/spandex bike shorts and actually detest nylon/lycra. But for the past several years all the bike shorts are made out of nylon/lycra. What gives? I'm sure some test showed that they might wick slightly better or have some other slight edge. But for me, cotton/spandex is far more comfortable and keeps me from sliding around on my saddle.
With nylon/lycra I'm always sliding around my saddle to the point where I can't settle in on my sit bones. And no offense to those that like how they look, but the shiny material for nylon/lycra looks like a bad 70's concert with Donna Summer. Really, I don't like 'em, and I cannot find simple cotton/spandex bike shorts anywhere anymore. I'm going to wear the last 3 remaining pair I have straight through if I can't find a source soon.