I have a set of populations which i have sectioned off by applying quadrants to the results. The statistics supplies me with a "percentage gated" in each quadrant and a "geometrical mean". Which is the best to use? The percentage seems so much more easier but does the geo mean add that much extra detail in any way?

It really depends on what you are asking or looking to evaluate. If you are looking to evaluate frequencies of subsets then the % gated information would be sufficient. If you would also like to evaluate the degree of expression (or absence) of a marker (or markers) on those subsets then a geometric mean analysis would come in handy.