I had similar questions in my thread on
buying a reconstructed title Prius. As pointed out, the Torque app, a $10 bluetooth Elm237 device, and download of the correct PIDs for the Prius will give you more info than you know what to do with. I inspected individual bank voltages to see that they were similar. My concern was that the battery might have been damaged from sitting too long while being auctioned and repaired. For a car that hasn't sat for a long time, I don't think there is much reason for concern about battery health.
I suspect that my lack of LRR tires is responsible for maybe a 3 mpg hit, although it's just a hunch of mine. It will be interesting to see what happens to fuel economy when I finally wear out the tires and install LRR.
I'm not very educated on the Gen II, and have no interest at all in the Gen I. I do know that in model year 2007 and newer, Prius rearranged the package options and made more features standard, if that is important to you.
EDIT: The forum has unreasonably small upload limits, so I have linked files I found useful to my Google Drive.
Gen III Prius User Guide
Gen II Package Guide
2010-2011 Package Guide