I don't know a ton about yours but I know he's taller than the Figma, and Saitama isn't meant to be very tall in the series. It adds to the effect, I suppose, little guy being so effortlessly overpowered. I like big bruiser figures but when a character is meant to be short I like them short. Like the Mirage Turtles, they're about five inches which is nearly right for 1/12.
Good choice on the cape, I want to sew a bendable cape for my Figma Saitama. Thinking about getting any food for the two of them? The characters lend themselves as much to action, like your photo, as they do to sitting and watching television.
My only real problem with the Figma is that he doesn't have that contented smiley face. THey have a happy open mouth one but not the one that I think defines him, that closed mouth small smile.