Well, I had a New 3DS transfer SNAFU.
Everything was going perfectly with the data transfer from my older 3DS XL w/ 2gig SD card to New 3DS w/ 32gig replacement microSD, thanks to the guide quoted above. That is, until I get near the end of the process - putting the microSD card in my PC. For some reason, my up-to-date Windows 8.1 PC doesn't recognize microSDs.
It works fine with standard SD cards, but nothing from the 32gig card I bought or
the 4gig microSD that comes with the 3Ds.
Fortunately, even though they say a PC is needed, I used my MacBook Air with an SD card reader built-in, and it did fine with both the SD card from the old 3DS and the new microSD card - the copy worked. *whew!*
So far I've only messed with a few things. The improved 3D is
nice, but not as perfect as I was hoping. I still see occasional flickers or lines on the screen that are slightly distracting. But the wonked-out double vision from moving while playing seems to be fixed, so that's great. I think the small glitches might have been a case of too-high expectations, so I'm sure that once I get used to it I'll learn to ignore the little issues and just enjoy the 3D.
EDIT: played some more, and impressed that the improved 3D can now actaully be used in "VR-style" - holding and moving the unit around as it changes the view. I'll have to try Face Raiders again, and pull out the AR cards to give them another shot.
Also interesting how much muscle memory plays into operating these things, because I'm totally stumbling searching for new locations of buttons, card slots, stylus, volume control, etc..