Quote: I don't like proprietary batteries that may or may not be hard to get in the future. I have a couple of electronics devices that had proprietary batteries that are literally sitting in a drawer unused because I can no longer get fresh batteries for them. . .
And everything else magkelly said!
Summary of my feelings -
1) They will always be available in the future. Had that happen in the long past with
proprietary batteries for radio scanners that became useless.
And some film cameras that I can no linger use if I should get the urge.
Sure I probably could track down the photo batteries but if they were AA's I could use
them if ever I wanted with no hassle. Again I look to the future.
2) If an emergency arises while traveling you can always get some AA replacement
that works. Worst case would be to have to buy a charger and batteries on the
go but at least you could continue to shoot for the rest of the trip.
3) You can (should) carry a set of non-recharg Lithiums with you and just keep
them as an emergency backup. They have a 12 year shelf life and work very well.