Saturday is always the most busy day. As for the turn out its the biggest thing in Rhode Island all year. The highway actually backs up for miles so your better off getting there early to avoid the traffic.
Also a big secret of mine is, if you get there for 7am ( gates don't open until 10) the sides streets right near the main entrance has parking meters spots. On Saturday it's fee to park! I literally closed my car door and walked into the door.
I will be with the r2 builders booth all day Sunday stop by and introduce yourself. I'll be wearing my name tag