Flight Deck 6500 v. 6501 v. 6502

[nyvram]

Hello, its been awhile since I posted (ok, 2 YEARS to be exact, but who's counting?) ;-)

My questions are hopefully fairly simple but I can't seem to find a straight answer on the web (or the search) for these questions:


Are the following all TRUE?
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1. 6500 seems to have the battery issues and they've been ironed out by the 6502.
2. None of these models support AM/PM time; only 24 mode.
3. FD Auto-on requires the user to first push the 'on' button to come out of sleep then it works as expected whenever you stop during your ride.
4. Regardless of whether you opt for the wired or wireless version, you're limited to hooking the sensor to the front wheel which sucks if you want to hook the sensor to the back wheel in order to have cadence available while on a trainer.

In addition:
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Other than the color of the head unit & support for the new 10sp DA, what else is different between 6501 and 6502? Should I opt for the cheaper 6501 & be done with it?

Why doesn't ShimanoUSA have the 6502 on their website?

Whats the least expensive computer w/ cadence that you can connect to the rear wheel?

How difficult is installation including the fact I have to swap the '2 button Ultegra hood' for the 2 '1 button hoods'? Will I end up insane and down at my local bikeshop?

Lickbikes.com has the 6502 for $38.99 & the wireless harness for $59 with $6 shipping. Does anyone know of anything cheaper on the net?

THANK YOU! Sorry to be such an information sucker. I really did try to do my homework on this before posting.