The issue with the "talking filibuster" is that it ties up 50 Party A senators to listen to one Party B senator speak while the rest of the Party B guys are out eating pizza and taking naps. Once you have less than fifty-one people in the chamber, someone (the filibuster givin' guy) can suggest the absence of a quorum and the session is adjourned if there's not enough people.
This is in part why the procedural filibuster exists, so they can skip the spectacle and get to the end result.