On my post emphasizing the distinction between Senate practice on legislation and Senate practice on nominations, a Senate staffer passes along an additional point that I should have made:

These categories [legislation and nominations] are so different that the Senate has completely separate calendars for legislative and executive business and must actually go into executive session to address nominations.

So again: Defenders of the legislative filibuster undermine their cause when they wrongly insist on a linkage between the nominations filibuster and the legislative filibuster.