I don't know that the workload will even increase for you guys and gals. Most people have at least $2 in their wallet.
All in all, I think this is going to work out well for US, and it is probably a good move in the long run. I didn't like it when I first heard it (not because it made me mad) - just because of the "impression" it makes. I'm a marketing guy by nature, and given how quickly this was executed, it was done as well as it could have been - BUT considering it is really an "industry" changing move, it could have been done in a more positive way... It is often easier to deliver a perceived negative when it is accompanied by a positive. I would have liked to have seen the addition of "premium" beverages and snacks for sale when the program launched so US could have at least taken the approach of, "times are tough, and we have to tighten the belt, but look at what we're now able to offer you". In any case, I think that water should still be offered for free.
I dont know the specifics behind handheld units for credit cards within your industry, but I am familiar with that hardware, and personally, I would just accept cash. Even though it SEEMS easier to just swipe a credit card, you now add other negatives. US will probably pay upwards of $400 for every unit they buy - it will break frequently - it will need to have the data "sent" to the credit card processor at least once a day - people will make mistakes and charge customers the wrong amounts, and voiding a sale is not easy, and on top of that, US will pay 3% of all its revenue to VISA/MC, etc. I would want to guess that, handling cash is cheaper than dealing with these issues.
Best of luck to you all with the new service. Life is too short to be a hater... We all have to just do the best we can with the cards we're dealt, no matter what industry you are in...