Frankly I find both of these really hard to wrap my head around. Not like football fields or olympic swimming pools are better, but the country of Finland being ¾ covered gives me a much better sense of scale than x million hectolometers.
Probably that only works for people that are from nearby Finland and/or into geography, though. For huge scales like these, I'm thinking degrees might theoretically be a better unit, since it's easier to visualize a fraction of the globe (presuming people know there's 360 degrees around the globe) than picturing hundreds of thousands of some other unit.