>Yes, the implementation of Auto ISO & flash changed on the >D300s and subsequent cameras. The camera seems to use Auto ISO >to try & get a 'correct' ambient exposure before adding >flash, rather than keeping the ISO low and adding more flash >to get a good exposure. I don't think many people like the >newer implementation, even though (for TTL-BL) it might be >argued to be more 'correct'.
This was the answer I was looking for. For myself and under my own conditions, the pre-D300s implementation has proved to work just fine and I prefer it, but I will adjust my technique accordingly now that I will be using the D300s and as I learn more.
Thank you to everyone one for your time and insightful responses.