It depends on a lot of things.
With people I don't know well, I'm extremely non-confrontational, unless I'm in an assertive mood and maybe someone's rights or safety is at stake. Most of the time, though, with strangers, I'm practically invisible, and I like it that way.
With those I'm close to it depends on my mood, what I perceive about their mood, how much I know about the subject at hand or how confident I feel about my position, how important the matter is to me, whether I'm tired, stressed, hungry, had enough sleep, have a migraine, am depressed, etc. Lots of things. In those situations I'm about 50/50 - in between.
I am overall more confrontational than I was when I was young. Which is probably, in my case, a good thing.