Nick,
One disadvantage to wheels in rocky ground is the ability to knock brakes and sometimes brake lines off the wheels. But in general...much happier on wheels than skids. Took some getting used to when steering the Chinook by the aft gear but having been a fork lift driver during high school it came to me pretty quick. You could whack all sorts of things with the aft blades if you were not thinking while making turns in tight places.