Droid 2 has physical keyboard and smaller screen. Battery may last a bit longer. Droid X has a larger screen and no physical keyboard. And the camera is better on the X
The keyboard on the droid 2 is surprisingly decent, though I still don't like the one piece rubber design that was carried over from the original, stiffer one, but perhaps I'm just biased against those kinds of keyboards. I've always had an easier time typing on chiclet styled ones, like on the Epic 4g or the Touch Pro 2.
