This is a phenomenal race, and very beginner-friendly. The distance is easier than the MCM, the medal is a unique military challenge coin, and the expo has a cool selection of Army equipment and vehicle displays (besides the traditional running expo). And there's nothing quite like thousands of runners and fans together on a beautiful course through the nation's capital!
The experience is especially great for anyone with ties to the Army. The post-race area is full of tents from different units, and you'll almost certainly find yourself running next to colleagues and friends from throughout your time in service.
My only quibble with the experience was the wave starts, while initially well-organized under different banners with colored balloons, slowly merged together into chaos in the later waves. But overall everything was very well organized and thought-out, from the water stops down to the busses from the finish area.