That's a good question. Good service is something important to the overall dining experience, so much so, higher end places regard the "maître d'hôtel" aka the service/restaurant manager equal to the chef.

Great service is generally about "reading your mind": e.g. providing you with a replacement fork that you dropped without you needing to ask. Also, coordinating that "timing" you are after, perfectly. Good service is attentive without being overly present. If you ever ate somewhere in a sitdown restaurant and thought after "wow that was a great meal", service contributed to that.