I hate 'notes at the back' style. If something I don't know comes up, I wanna glance at the notes at the bottom and know what the hell it is now, instead of having to flip to the end and read something like
(2): A cha no yu was a blah blah blah...
and then go back to where I left off. Call it personal preference, but I prefer it when notes are on the same page as the thing they're explaining.
Haven't watched much anime that needed notes like that, though.