the biggest difference that results in, is how much force of contact there needs to be to get a response. And my understanding is that the N900 have the most sensitive resistive screen yet. heck, one can often tell on videos if a person is used to the opposite sensor tech, as they will invariably en up touching the screen in the wrong way (nail on capacitive, flat of finger on resistive) and make some noise about lack of response.
They're maemo and MeeGo... "Meamo!" sounds like what Zorro would say to catherine zeta jones... after she slaps him for looking at her dirtily...