I say give the staff a raise and add that to the menu price. That way you would have a better idea of what your bill will be before you order.
Those handheld card readers are becoming more common, though I've always seen an option for a write-in tip. I suspect that the suggested amounts with the highest being the default is intended to make the customer feel like a cheapskate if he selects something lower while the server is watching.
If I'm feeling generous, I tip 20% of the pre-tax amount, with cents rounded up to the nearest nickel unless I'm paying the tip (and usually the bill, too) in cash, in which case I'll usually try to come as close to my calculated tip with the bills and coins in my pocket, and I'm not embarrassed to ask for change from a larger bill.
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