Warning! Spoiler for Marvel #2 below!
After the events of Marvel #2, "The Vision Unphased," by Paolo Rivera and Clayton Cowles, we now see a closer kinship between Captain America and Vision. These two heroes have always carried a certain "otherness," about themselves. Cap with his slightly antiquated yet nonetheless potent personal moral code, and the Vision's never-ending journey to understand humanity and thus become more human. But both Avengers are more similar than we think.
One character trait and subsequent flaw both Cap and Vision share is their innate sense to care and show concern for their friends, even though oftentimes they both have a bit of difficulty showing it. Like many leaders within Marvel's teams, Cap shares the same unflinching stoic attitude similar to X-Men's Cyclops. When it comes to evil rising its head, Cap won't back down and he won't look away, especially when it comes to his guiding principles of right and wrong. This might make him seem cold, maybe even emotionally distant. But unlike the grim visage of Batman, Captain America goes into, "soldier mode," when he and the Avengers have a job to do.
The Vision also has similar mannerisms, but more coming from the fact that he's a synthetic human built from the part of the original Human Torch, and carries the brain engrams of Wonder Man. Seemingly a contemporary "Frankenstein's Monster," Vision tries all he can to better understand humanity as he searches for his own. This can often make the Vision seem like he's the Avenger's version of Mr. Spock, with an often expressionless face and his seemingly cold, machine-like logic. Yet, Vision is more than capable of feeling, of making friends, and even falling in love and getting married, as he did with Scarlet Witch aka Wanda Maximoff. While human emotion doesn't come naturally to Vision, he has shown to be a quick study.
What's also a noted similarity between Cap and Vision is how both of them created their own surrogate families. For a brief moment in time, Steve Rogers raised and mentored the son of the TV-chested villain, Arnim Zola. With Cap and Ian Zola trapped in Dimension Z, a place where time flowed at an accelerated rate, Cap knew he had a limited amount of time to help Ian break his brainwashing to make sure he didn't end up like his villainous father. While the super-soldier serum kept Cap from aging, was able to save Ian's mind and kept him from his father's clutches.
Likewise, Vision tried his own hand at the family life in different iterations. He and Wanda's twin children, created from the soul of Mephisto, were once thought lost until they were reborn as the Young Avengers Wiccan and Speed. Later, Vision would make an attempt at a quiet home life with a wife and two children, who were also synthezoids. Created in the same lab where Ultron created him, Vision "assembled," his own family at what he felt was his shot at a life with a family.
While the Avengers have been defined by their wild differences, on a deep character level Captain America and Vision have a deeper bond share many core values. Because sometimes a good person can come in all shapes and sizes, whether you're made of flesh and blood or vibranium.