The advantage is living a holistic, truthful life, where G‑d isn't relegated to the synagogue and barred from the dining room and kitchen. By observing the kosher laws, we are mindful of G‑d and connect to Him even as we do something as mundane as eating.
I have yet to discover a disadvantage to eating kosher. Challenges perhaps, but not disadvantages. The challenges are obvious. You can't buy food everywhere, trips on the highway for extended periods of time require pre-packed food, etc. But these are things you get used to, and with time they cease to matter.
Check out our comprehensive Kosher Section for more info.
Rabbi Moshe Goldman for Chabad.org