idle rpm problem?

[skm]

just came back from deler for a 2000km new car service(just checking)
find my car's idle rpm as follows
stopping on a red light with the gear in D 550rpm(almost no vibration)
stopping on a red light with the gear in N 650rpm(feel vibration)
it is very obvious when I shift the gear from D to N while stopping on a red light the rpm goes up and you can feel the vibration from steering wheel.
I don't have this feeling before the 2000km service check
the engine temp is normal(already reach the working temp)
anything wrong?