Adam Liptak's article in the New York Times describes the Supreme Court as presenting a heavier and much more complicated workload for newly confirmed Supreme Justice Sonia Sotomayor. Well, he is only partially correct.
The case load of judges in the courts of appeals is actually much larger than that of Supreme Court justices. The Supreme Court has discretionary review, and it only accepts a handful of petitions for review (this fact made the conservative effort to show Sotomayor had a high reversal rate a ridiculous venture). By contrast, the courts of appeals must render decisions in all cases presented to them.
The average case heard by the Supreme Court, however, tends to present more interesting and complex legal issues. Often, the cases have split the lower courts, indicating that the law is not fundamentally clear. According to some scholars, Supreme Court justices with prior appellate experience often take advantage of the new job and write broader opinions and more passionate dissents than they did as appeals judges, where consensus-building was far more important (given the panel structure). Although first-year justices are normally fairly reserved, sitting on the Supreme Court allows for greater depth and reflection than the normal appellate court position.
Update: David Bernstein of the Volokh Conspiracy agrees with me -- but he is less kind to Liptak's idea than I am.