Justin, I have a bit more data on the speedometer issue, but I'll address your question first:
I am curious if you see the same thing, not just at power on, but also right after pressing and holding the reset button?
It never happens after a reset. It always happens after a poweron.
Now, a bit more data:
1: If I am already moving forward at a decent rate of speed (pedaling) when I switch the unit on, I don't see the phenomenon as dramatically on the realtime speedo display (it might only get up to 50-100 MPH) however MaxS still records a peak in excess of 400 MPH.
2: If I switch speedo units to Km instead of Mi, the glitch goes away completely
. When I switch back to Mi, it comes right back.
3: I may have been mistaken about this being new in b15. As I was poking around, I remembered that my MaxS reading has never been correct (going back to when I got the unit with, IIRC, b12 or b13 code.) It has always displayed a value in the neighborhood of 400+ MPH. I didn't know what to make of this at the time, but it now makes total sense, at that's around the peak it hits during this power-on glitch. I'd never noticed it before, but I'll bet this has been happening since I first installed the unit. I left my laptop at the office, but I'll try to revert back to b13 or b14 to test this theory.
As for the Wh/mi glitch I noted, I have been keeping a close eye on this, and I have not seen it re-occur since the original instance. I'm willing to write this one off to cosmic rays, or perhaps a sign that I should cut back on the amount of LSD I consume when I ride.
The concept of "average" requires that 50% of the population be below it.