Hi Ted,
The latest software version is 6.4. I'm not sure what advantages it has over 6.3, but it's noticeably slower. "Sigma slower"!
The detail function looks like a hybrid between a slider and a button. You might describe it as a series of buttons that range from 'softening' the image details to 'crisping' them. Whatever crispy is I'm not sure.
One thing I've just learned is that the latest firmware for their cameras is very good. For the Quattros it's a big color improvement.
Worth checking out if you haven't done already.
Richard