I agree with you about the convenience of larger-denomination coins. I regularly spend time in Canada and really like their one and two dollar coins. I think it's much easier to reach in your pocket and pull out a coin or two than to fish through your billfold to pay for a cup of coffee.

Printing and replacing paper currency is expensive; coins are easier to sort, last a lot longer, and will save money. We just need to find the political will to drop the one-dollar bill. Sure, some people will squawk, but they'll get over it.