I used high quality dual-pane, argon-filled glazing. Unfortunately, there wasn't much thought about solar heat gain coefficient (SHGC) in 1991 and my windows are low SHGC. The house collects far less heat than you might imagine from all those south windows.
In addition, I was concerned about resale so I used conventional wood frame floors with wall-to-wall carpeting. This doesn't provide the thermal mass needed for a true passive solar design.
The house works pretty well in spite of these limitations. The lessons learned are to use high SHGC glazing for south facing windows and insure that there is enough thermal mass on floors or walls that directly receive sunlight to absorb heat during the day and release it slowly at night. Here is an excellent link on high solar gain glazing.