just wondering what everybody feels like the best OS version is for maximum battery life?

is there anywhere i can see a listing of all the OS software versions available for the 9780?

Look at the top of the 9700 section. I think they should be there. I know the latest ones are.

You might also read through the 9700 section and use the SEARCH feature to see what you find. I know it has been asked before, but I do not recall the response.