I think Dune2000 had no Dune atmosphere, it was made too command&conquerish, my biggest disappointment was, that the "Troopers" were now just like the rocket infantry in the C&C serie, not the superior Harkonnen infantry it used to be in Dune2. And although they made the game almost exactly like C&C, they did not put in those short movies after each mission, but only a moderate intro and a ridiculous short outro.
Of course, that's only my personal, subjective opinion.
Plus, I bought the German version, which is very annoying, but that was my own fault.