I did a Master's degree in CS and have absolutely no regrets. It was, without a doubt, the most enjoyable, interesting, fun and educational period of my life.
In the 20 years since I have, at some point, found almost every subject that was covered useful. Most useful of all, though, was the education in critical thinking, critical systems thinking and soft systems. The lessons I learned there are ones I still use every day. Almost every job in technology involves, in some form, solving complex problems in complex, continually changing environments with many participants with differing interests, motivations and capabilities. This has stood me in good stead from my first job as a developer to my current role managing large programs of work.