The point is that exactly as you said, older phones can do this just fine...and on this newer device it's supposed to be perfectly smooth...which it is not. That's the problem. The 2nd problem is that there are other devices out there right now that do this perfectly smoothly giving Nokia 0 excuses.
The Droid uses a capacitive touch display, as do most Android phones. The Droid's touch interface was a little bit twitchy. I don't know if it was as screen issue or a processor/system issue, but every so often there were short gaps between pressing the screen and having the Droid react to what you wanted. I noticed some slight stuttering and lag in screen transitions, especially from the home screen. Many will blame the processor for this. The Droid runs a Cortex A8 processor at 550MHz. Motorola claims that the processor can run up to 600MHz when required by certain tasks; 550MHz is merely the base speed. Tech mumbo-jumbo aside, you may notice some laginess in the user interface and it isn't necessarily related to a bad touch screen.