I've done this before, and I have an opinion of course.
On my KTM, my GPSmap 478 would drain the battery completely in 2 - 3 days if I didn't run the bike. And I've spoken to at least one ST1300 rider in Canada who confirmed this, even with this unit switched OFF.
If tied into unswitched power (I'll use the Quartet Harness), this is not a possibility, correct? Assuming no underlying power / electrical issues, of course.
I haven't hard-wired any of my handful of GPSs to the ST1300 yet, been using internal battery or power outlet.
Now it's time to make it sortof permanent.
Let's get this thing started!