In CS, the difference between high and low Trust is very noticeable; it's a big change when your games with silent / mostly-nice teammates and enemies start to become slur-fests. The value itself is not visible to the end-user, but its effects are certainly felt.
Now that you've written it out, it explains why my solo games are better than when we queue with a friend, who never plays outside our games together. And I end up promising "I just had nice team mates the last game!" :)