Well such things was in medieval also, banking has quite long history, thats will be nice to see good economic system, where gold will actually have weight as currency and as item again, but does devs will implement such feature?
Of course, a decent economic system would have more values of coins, instead of everything being "gold", with a meal costing 2-5 and a house costing vast piles. Low value coinage for low value items, and high value coins (or gems, or notes, or whatever) for rich folks, governments, and land transactions. Part of the reason we need to be able to carry vast quantities of coins is because we only have one denomination that has to work for everything from a glass of ale to a castle.
...not that I'm saying change the TES system. I've got no personal problems with weightless coins or the lack of a banking system. :shrug:
(Weighted coinage has always seemed to me to be one of those pen-and-paper RPG things that's there so the GM can mess with you. "Grats, you killed the Copper Dragon! It has a hoard worth 500,000gp! Too bad it's all in COPPER PIECES! Bwahahahaha! Hope you brought 80 workers and a fleet of wagons, svckers!" :rofl: )