Guests preference: Cocktail & hors d'oeuvres vs. Seated dinner
Do you think that a guest who does not know many others at a wedding reception would be more comfortable floating around the room and mingling or would they prefer to be assigned to a table where they might find it easier to strike up a conversation with strangers? What type of reception would you prefer to attend if you did not know any of the other guests?
Both has its merit and we are all different, so it is difficult to state one way or another. If it is a seated meal, the guest would most likely be drawn into a conversation. If a person is very shy, he may not mingle if it is a cocktail party. But, some would rather not be stuck at a table with those he doesn't know. So... choose what you feel is most appropriate for you and the formality of your event.
It is very respectful of you to consider your guest's comfort. Bravo!