I got my MS about twenty years after my BS. The primary value I got was a fresh appreciation of the "science" in Computer Science. I went in planning to focus on software engineering and bioinformatics; two very practical offshoots from my professional career. What happened instead was I fell in love with theory -- automata, theory of computation, and graph theory in particular. I don't know if my MS has been particularly influential in causing companies to consider or hire me, but it has certainly deepened my appreciation for what I do professionally, and it also influences the topics I pursue personally.