I can't choose between FF and HP because I have such mixed feelings about him.
It's obvious he cared more about the Supreme Court than the Presidency. During his Presidency, appointing Supreme Court Justices was his favorite activity! He's the most bipartisanly magnanimous appointer of Justices we've ever had: he made six appointments to the Court and they were an equal number of Republicans and Democrats. None of the six appointees, though, were noticeably liberal; the three Democrats he appointed were all southerners.
He persuaded Congress to pass a law that allows the Supreme Court to choose its own docket, instead of being required to hear all of the appeals that were being requested. He persuaded Congress to construct a Supreme Court building, so that the Court could get out of the cramped space they occupied on Capitol Hill. He persuaded President Harding to appoint George Sutherland, Pierce Butler, and Edward Sanford to the Court.
But Taft's reign as Chief Justice is notable for his heralding of conservative judicial activism. Taft's own appointee Willis Vandeventer teamed up with Sutherland, Butler, and Wilson appointee James McReynolds to form the "Four Horsemen of the Apocolypse." They and Taft worked together to strike down a lot of state laws, under the Fourteenth Amendment, to strike down state laws that should not have been struck down. Right after Taft retired, Justice Holmes complained, in a dissenting opinion:
I have not yet adequately expressed the more than anxiety that I feel at the ever increasing scope given to the Fourteenth Amendment in cutting down what I believe to be the constitutional rights of the states. As the decisions now stand, I see hardly any limit but the sky to the invalidating of those rights if they happen to strike a majority of this Court as for any reason undesirable. I cannot believe that the Amendment was intended to give us carte blanche to embody our economic or moral beliefs in its prohibitions. ... [W]e ought to remember the great caution shown by the Constitution in limiting the power of the states, and should be slow to construe the clause in the Fourteenth Amendment as committing to the Court, with no guide but the Court's own discretion, the validity of whatever laws the states may pass.
That was from
Baldwin v. Missouri, 1930. Holmes always dissented from the judicial activism perpetrated by the conservatives on the Court.