Is research experience or GPA more important when applying to MSCS programs
The answer, here, is that it really depends strongly on the individual program, since Masters programs vary much more than Ph.D. programs in both their purpose and organization.

For some programs, you can essentially get automatic entry based on grades alone (my own Masters was that way, for example).  For others, research and recommendation letters may weigh in significantly, especially if students are funded rather than self-funding. Research does generally weigh much less than for a Ph.D., however, particularly since a Master is often expected to be a terminal and industrial-focused degree.  

Thus, in general, GPA is significantly more important than research, but the degree to which this is true varies wildly by program.