> But if tipping is virtually mandatory, and you end up paying the same amount, what difference does it make to abandon the tipping system, other than to make it more equitable for the staff and more convenient for the customers?

Psychologically, I'm sure it's not the same. The number on the menu is what sticks in the head, and the rest comes down to miscellaneous other expenses that people don't think about unless they make a point to.

As much as I'd like to go to a system with fully-paid servers and optional tipping, I have to admit that if I saw 20% higher prices on the menus, I'd be put off unless I made a point to remember, oh yeah, I'm saving on the tip.