It is helpful during federal criminal proceedings to be represented by a lawyer who is familiar with the federal rules of evidence, federal rules of criminal procedure, trial procedure, and the federal court system in general. The lawyer should also be familiar with federal sentencing procedures, and with the recent Supreme Court rulings which affect sentencing. It helps to have a defense lawyer who is familiar with the U.S. Attorney's office which is handling the case, and ideally some familiarity with the federal investigative agency which spearheaded the investigation.
There is no such thing as a highly qualified federal criminal defense lawyer who dabbles in federal court matters. Lawyers either know federal criminal defense, or they don't. If you are involved in the federal criminal system, make sure your lawyer, or at least one of the lawyers who will be serving on your defense team, has extensive experience with the defense of federal criminal charges. As previously noted, federal criminal defense tends to be very expensive. You will be paying for specialized experience - so make sure you get it.