The reason for the different sizes is so that blind people can know what bill they have. Right now, they just have to trust the person they are giving money to.
Probably a minority here, but I think the money we have now is better than these designs. We keep changing the designs to be less beautiful each time. Its sad.
Like I said, I am a minory with my opinion. I find beauty in the designs on the bills now and all of our bills and that's why I collect them. If all you can see when you look at our money is faces of historical guys, then there's no way I could ever make you understand.
It seems better (easier to differentiate) for vending machines and other automated small transactions.
I don't know about you but I think the art on these looks a lot better then the monochrome faces of historical guys you have now.