Having now seen more of the 1980-era 'Wheel of Fortunes' that are now circulating I believe the addition of the bonus round was a big reason the show became such a hit in syndication. Without it the show begins to drag at the end and comes to a dull finish when the players are just playing for the right to come back the next day. The main game played much better with a chance to potentially win a car at the end.
Once the bonus round was in play the rest of the stars began to line-up. Pat was different from Chuck but in a good way as Nancy Jones said on the Wheel 'E! True Story.' Vanna was more glamorous than Susan Stafford in my opinion. The addition of Jack Clark and completely new music made a difference too. Finally there was timing. 'Family Feud' and 'Tic Tac Dough' looked tired compared to the flashy new kid on the block.