love riding in the rain, if the wind is not blowing.
Hate wind whether it is raining or not.
take or keep at destination spare clothing. sitting in wet clothes for 8 hours sucks.
I use a poncho, and I like the fact that it does not keep the sweat in. in a light warm rain, I just get wet (similar to when i am riding in the heat...).
wipe dry and change at destination.
You go.

never had any problem with slick streets.... if you are concerned, give yourself extra time, and walk around hazards.