Elena Kagan Lack of Judicial Experience?

Unable to knock anywhere else, the knock on Elena Kagan is that she has no judicial experience.  I took a look at the last 19 judges on the Supreme Court.  Roberts and Thomas had two whole years each on the District of Columbia Court of Appeals before joining the Supreme Court.  Scalia and Thurgood Marshall had four years on the court of appeals, and John Paul Stevens five years - total judge experience.  And I don't think that being on the court of appeals is exactly what the public would think of as judicial experince.  

Of the last 19 judges going back to the 1962 appointment of Byron White, only three sat as judges on a trial court: Sonia Sotomayor, six years as a district judge in New York; David Souter, five years on the New Hampshire Superior Court; and Sandra O'Connor, four years on the Arizona Superior Court.  Five had never been a judge; White, Goldberg, Fortas, Powell and Rehnquist. 

The most experienced judges?  Sotomayor 17 years on the bench; Alito, 16; Breyer, 14 (usually considered an academic); Ginsburg (academic), Kennedy and Burger, 13 years each.