I've flown ANA once (on a return trip to Japan) and indeed, all their staff are very professional and willing to make things as comfortably for you as they possibly can, but they are also very strict when it comes to upgrading. On a full flight in Y, they'd rather upgrade a whole string of pax (C to F, Y+ to C and Y to Y+) just to free a Y seat for you, than to give you that F or C class right away.

BTW, it seems the concept of 'upgrading' non-revs to higher classes is something not really widespread in Asia, to say the least, but other than that, they are great.

Carfull if you fly them domestically though: on some planes and routes, they have very cramped seatpitch and while they generally try to put tall people at emergency exits or on first seatrows, ZED ticket holders are simply given whatever seat is left, so you can find yourself offered a seat where you'll need a shoehorn to get in to! On intercontinental flights, this is no problem.