One is the level of realism. Unlike the `forensic specialists' in the Numb3rs series 1-6 dvd, the `science guy', Professor Charles Eppes, never goes running around after bad guys or knowingly puts himself in dangerous situations. That is left to his brother, the Supervisory Special Agent of the FBI, Don Eppes and his team. The other side of the equation is that when Charlie does his stuff, you can get much closer to the technique he is using than you can with either Abby Schiuto or Temperance Brennan unless you happen to have aced a course in anatomy. Math is something you can explain entirely in words and symbols which can come across on the screen. This would even have been a great radio premise, if this kind of show were trendy in radio days. I confess I am much more comfortable with set theory, Venn diagrams, and Fibonacci numbers than I am with tibias, fibulas, and kerf marks. Similarly, the FBI action part seems far more realistic than what we see on Bones or Criminal Minds. I believe the FBI agents do not operate like Seeley Booth, as one man operations, or like the profilers in Criminal Minds, who often find themselves in gunfights, even the geeky one.