I see a lot of differences: * Internal combustion engines work in Antarctica. * The atmosphere is breathable. * The atmosphere is livable if heated first. *

I see a lot of differences: * Internal combustion engines work in Antarctica. * The atmosphere is breathable. * The atmosphere is livable if heated first. * The gravity is the same as Earth. * (I'm guessing) more sunlight falls on a given area of Antarctica per year than Mars. * There's no communication delay with Earth. * Earth-orbit communications satellites are reachable from Antarctica. * The ground is covered in water, if you heat it first (I don't know how useful this is, but it's probably more useful than Mars soil) and finally: You can come home from Antarctica.