The main benefit I can think of for the military is the ability to approach zones that have anti drone equipment via the ground. Noise isn't really a concern since grenade drones fly too high and kamikaze drones rely on speed and unpredictability. Not sure how much better approach on wheels would be than just flying low, either.
The tradeoff is presumably higher cost and less reliability. Additionally, less ability to carry mass than if it just flew.
I can't imagine a way this would be too useful but obviously a lack of imagination isn't proof..
The obvious weakness are the wheels. Conventional infantry are already trained to hit armored vehicles in the wheels/drivetrain to remove their mobility. Hitting a wheel for this robot accomplishes the same for driving and flying (since the rotors are part of the wheels)
Although I don't think militaries would really rely on wheeled transportation much for drones, though perhaps reduced battery drain in the wheeled on-ground mode is a selling point for longevity in the field. It certainly has many other uses though.
