A website I check out pretty regularly -- Tacticular Cancer -- has an interesting article on the 3 major 4X strategy games released this past year: GalCiv II vs. Sword of the Stars vs. Space Empires V.

I don't necessarily (and in fact definitely don't) agree with all the observations, but it is worth a look at as it is well reasoned and well written and makes some astute observations along the way.

Check it out.