It depends on your shoes. With my Sidi T3's and Sidi Terra's I never have to wear socks.

I go sockless for sprint, Olympic, and half iron. One of my main shoe criteria is how comfortable they are without socks. I use gold bond powder in my shoes, helps keep them smelling nice, and pre-apply bodyglide in any potential hot spots. I don't bother drying my feet either, just strip my wetsuit, helmet on, grab my bike and run. Part of this advice is for running shoes I realized, didn't see until later that you run in socks.

Socks for 70.3. No socks for sprint/oly.

---

@floathammerholdon | @partners_in_tri

I've never worn socks for a 70.3 or less.

I took the few seconds in an IM though for the run, see how training goes.

Same. I suppose it depends on the person, shoes and if they're prone to blisters. I was a bit reticent about going sockless for a 70.3, you don't want to find out halfway round the run course that you should have worn, socks, but they were fine in multiple ODs so.. Probably wear socks for an IM.

x2.

Having said that you can probably get the right pair of socks on in about 10 seconds in T1 and if you feet aren’t conditioned or shoes aren’t right for barefoot running (and to a lesser extent, biking), you will lose more than that in the pain of cuts or blisters etc

It all depends on your shoes and feel. Everyone’s feet are different and all shoes made different so it’s more of a personal preference. When I started doing triathlons I took the time to dry my feet and put on socks. I was averaging about 2:00-2:30 in T1. After realizing how much time you can save I just step in my towel for a quick dry and run to the bike mount line. My T1 is now around 35-45 seconds. If you’re not worried about time and winning and it’s more comfortable, take the extra minute. It’s better than having blisters for a few weeks after the race.
On a side note. I did my first 70.3 last year and although my bike was fine with no socks, at about the 15 km mark on the run I started to feel the blisters. Between sweat, running through puddles, dumping water on my head and the mist of Niagara Falls, my feet were drenched. I will probably wear socks from now on for anything more than an Olympic.