I did actually meet an online friend a few years back who turned out to be nothing like I imagined...at least from our conversations.
My point is character like you rightly said isn't something we can just estimate. It's something we have to build up on others
I have had the opportunity to meet a few Steem people and most of the ones that have put themselves out there in various ways are quite similar to the reality, others not so. I find the difference the greatest between friends I have in the world, and their Facebook/instagram profiles.