Some of the most explosive big gill action for me occurs during Sept/Oct......In September I throw 1/4 oz spoons at fish that are pinned to the bottom in 30+ feet of water (FOW) http://www.bigbluegill.com/video/geneva-9807
The gills in Eastern Iowa are ramping up now. Fall is a great time to catch them as everyone else is out hunting. I just caught two over 9 inches and several more in the 6-8 inch range. They seem to be putting on the feedbag before winter gets here.
Here in Mid-Michigan fall is a great time for bluegills.They seem to run bigger in the fall and the lakes are less crowded,Jet skis and speed boats are not around.