Socks do wick away sweat better none, and the smell of my shoes after a few runs with no socks is quite bad, I'm sure there's some bacteria build up in them also. I notice a light film of dead skin on the sockliner overtime, pretty gross stuff.
For regular runs socks are more comfortable for me, especially cushioned ones like Thorlo. But whenever the pace picks up on hard surfaces and I start running on my toes more, the heat and friction is unbearable.
I should of stated earlier that the heat,friction, and pain only occurs underneathe my foot. Funny enough socks do provide protection on top of my foot, where seams of the upper are located, although it's not that much of an issue.
This is why I like(training runs)socks and dislike(workouts/racing) socks.