I have 2 high end Townsquare S toilets in my home and had on each the traditional soft close elongated seats.  Both toilet lids have snapped in the last 6 month from back hinge to almost complete front on their own.  First one I wasn't home when it occurred.  Second recently happened i was in the master bedroom when the master bath toilet seat lid broke.  All I heard was this loud bang, went to inspect what happened in washroom the lid which was closed was snapped (single person household, no pets).  Its obvious the resin the lids are made of aren't designed for the long term (near zero use, new model house but 6 years old, first occupant) pressure of the hinge spring for the soft close function.