My family of 3 (me, DH, and DD) almost always shares at non-buffet or family style TS places. We usually have 1 appetizer, 2 entrees, and 1 dessert, and we walk out satisfied- not stuffed, but not still hungry. We have never had any problems sharing, and never had any CMs tell us we couldn't. Some of our favorite places to share are:
-Plaza at MK
-Spoodles (we sometimes do a meal of all appetizers, tapas-style) at Boardwalk
-Restaurant Marrakesh at Morocco pavilion in Epcot
-Mama Melrose at DHS
NOTE- we do feel that the servers deserve a bit larger tip from us than the normal 15-20%, since they are working as hard, but we will have a lower bill than others. We usually tip closer to 25-30% when we share. JMO.