It depends on the environment... Really. But if you are in a conservative company I would say kid.
I have a rule I don't wear black patent to work, nude patent is ok, but black patent no. But I work in a very conservative place
I work at a law firm so naturally I would say kid leather. That could be because I own mostly kid leather and no patents. I hate the noise they make when you accidently brush one against the other when walking and it sometimes leaves a mark!
I think that if you don't work in a conservative environment and can be more liberal about the dress code I'd say it doesn't really matter.
I have been working in one of the most conservative environments, i.e., investment banking.
I wear patent as well as kid. I even wear my exotics (conservative colors) to work. I have been in the industry long enough and people know I get the job done and more so that might be why nobody makes a fuss, but even when I was a new to the industry right out of college, people never complained about me wearing patents.