Considering once (under the influence of alcohol) I took a dump infront of a security camera outside a music college I tend to find taking a dump in public pretty easy. If there's four walls around me I can go, if there isn't four walls around me but I'm off my face on the alcohol... I can go.
I dont like going into public bathrooms unless I absolutey have too. I just dont like the idea of having other guys who I dont know touching the same toilet as me. Plus I dont like the idea of other people around me like that, even with the walls.