I don't space bar convos I haven't seen yet.
also, sure it's nice and dandy if you're character is what all the auto-dialog does, however.
my shepard wouldn't have dreams about people that died around him, in 1,2 he was a callous dude (the ruthless option when you create him) and always put the mission first.
and he certainly wouldnt say "good to see you" to commander bailey when he greets you on the citadel. they ruined the control(you know, the RPG part) over shepard.
2 vids showing the difference in choices:
ME 3, 1 choice, rest auto-dialoged.
http://www.youtube.com/watch?v=x354hQAcM10
ME 1, you choose what he should say
http://www.youtube.com/watch?v=G2sZbKxi9sU