Stephen Richer, now a 1L at Chicago Law, does a good job summarizing the arguments alleging (and the better arguments refuting) the myth of a Supreme Court biased in favor of business, including my refutation of the surprisingly sloppy readings of the data in the Lee Epstein/Landes/Posner study that prompts much of the complaints.
One mistake: he forgets that the Supreme Court doesn't just review lower federal courts, but also state supreme courts—and, as Michael Greve has noted, the constitutional structure anticipates that state supreme courts will biased against out-of-state businesses in favor of in-state plaintiffs, and thus, as per Federalist No. 80, federal courts are meant as a check against this anti-business bias. Thus, we would expect a federal reviewing courts to rule more often in favor of business when they exercise discretionary certiorari jurisdiction, and there is a very good argument that the Supreme Court has not been pro-business enough.
One omission: the Andrew Pincus Senate Judiciary Committee testimony gets in the weeds of some of the particular allegations against the Supreme Court.