The only things I've done with the e-tube software, via usb cable, are:
Setting the multi-shift.
Upgrading the firmware -- easy. The newest firmware doesn't have anything I need, so I'll leave it as-is.
Multi-shift 3 cogs
(My Ultegra Di2 was set to "shift all cogs" on a long press -- not useful at all.)
I used the etube software to set it to
shift 3 cogs with a "
long press"--that's holding the paddle for about 1/2 second or longer.
At the base of a hill:
Hold down both bottom paddles. That shifts small front ring, and 3 smaller cogs. Simple and fast. From there, I might need to shift one more rear cog.
Over the top of the hill:
Hold down both top paddles. That's big ring and 3 larger cogs.
I shift the front rings way more often than I would on a mechanical bike. It's fast and accurate every time. I'll even shift to the small ring for a tiny 30-40 foot hill that might be just a dozen pedal strokes.
Shift adjustments
As you know, adjusting the shifting is very easy. See page 64 of the dealer manual. (First, set the limit screws with a screwdriver, one time.)
Hold the front control box button for 5 seconds until the red light comes on.
Now the up or down paddle will "micro shift", up to 32 adjustment steps, moving the derailleur a tiny amount at each click. It remembers the adjustment, so just press the button again to go back to normal mode.
(If you have two wheels that align slightly differently, you can just remember how many clicks in one direction, and just do the same count in the other direction when you change back to the original wheel.)
Downloads
download the Di2 dealer's manual. It's easy to follow.
si.shimano.com/pdfs/dm/DM-UL0001-03-ENG.pdf
And the E-tube PC software is here:
e-tubeproject.shimano.com/about/