The first Aussie banknote to appear in polymer was a $10 around 1988 or so. It was despised by most people (myself included), and was promptly subjected to all kinds of “tests” to prove that it was no good: “hey, I ironed it, and it shrank”, or “I accidently put it in the oven on maximum setting for three hours, and now it doesn’t look so good”.
Now, the notes are all polymer, and I must say I like them.
Pros: Interesting, high-tech, rugged and durable, very hard to counterfeit, slightly less germ-laden.
Cons: They will survive the washing machine, but not the iron. they are hard to fold, so keep them in your wallet, not your pocket (where they will spring out). They are generally very hard to tear, but if they get a small cut in them, they will tear very easily (a bit like ripping a T-shirt in half is easy only after you’ve cut the hem).
We also switched to $1 and $2 coins in the 80s, and got rid of 1c and 2c altogether in the 90s. I think this is a good thing. I’ve heard some Americans complain that they spend too much this way because they aren’t used to coins having any significant value. This may be true, but I think I tend to spend less because it encourages me not to break notes as they suddenly seem more valuable.
I think America should go to plastic (and possibly coins for the lower denominations), if only because of the huge number of fake US bills floating around all over the world. Be prepared to hate them at first, but you’ll get used to them.
The other issue is the use of different sizes and colours for different denominations. I grew up with this, so I’m used to it. I’m always nervous using US currency, and double check it before I hand it over. I’m not sure though, whether it would be suitable for America to convert. Your currency is such an institution, and is quite stylish the way it is. And you guys seem to be used to the one colour and size.
But definitely go plastic.