If I understand the news reporting on this, the Repubs didn't use or threaten a filibuster with the Clinton appointees, they used a parliamentary tactic of a Senator placing a "hold" on the nominee. Likely the same outcome as the filibuster threat we're seeing now, but not a filibuster, just the same.
When Clinton was President, the GOP controlled the Senate most of the time and thus never had to filibuster. If you are the majority, you control when things come up for a vote. Majority matters.