I agree that it's up to the individual. People have their preferences. We really like buffets at breakfast, because we're typically starving and love being able to eat right away, eat whatever we want and eat as much as we want. Plus, you get characters. We've never tried buffets at other times, though we will be on our upcoming trip, and are looking forward to the variety the lunch and dinner buffets will offer.
As for family style, we have had our meals that way at Liberty Tree, Garden Grill and Ohana, and absolutely LOVED it!!! You get a lot of food, they bring back whatever you want more of and the food in each of these places is excellent.
We tend to do the sit-down types for dinner, intermingled with the other choices, because sometimes you just want to be waited on.
Have fun!