I see this asked often.

I am buying Giro Privateer today (Masherz has a discount code).

I would like to know if they run "true to size".

For reference, my contribution:

I wear size 12 to 12.5 in Nike, Mostly 12. (Nike calls it 46)

I wear a size 46 exactly with Forte Traverse shoes from Performance Bike. (awesome shoes, but the laces are a pain). These are tiny bit smaller than most Nike, but that's OK with thin cycling socks.

I wear a size 12 exactly in a Five-Ten Impact Low.