We should transition to the Metric system because the rest of the world (except Burma and Liberia) uses it and because it is much simpler to understand.
Each type of measurement has a base unit ('gram' for mass, 'liter' for volume, 'meter' for length) and the entire system uses a consistent set of prefixes (e.g. 'kilo'=1000, 'centi'= 1/100) that says how much of the base unit is being discussed. Our current system, by contrast, has such arbitrary and confusing relations as 8 fluid ounces in a cup, 16 (different) ounces in a pound, and 12 inches in a foot.
Changing to Metric would simplify the teaching and learning of math and science (everyone can divide and multiple by 10). Going Metric would also simplify international cooperation on research and economic development projects.