Ate in a restaurant in Manhattan a few days ago. On the wall and printed menu, there was a large notice that "18% gratuity was included". one of our sons had eaten there before and said the food was great. It was, large portions and the service was excellent - none of us could finish our meals and they boxed the remainders for us. When they brought the CC machine to our table to pay, the server said right away "the tip is already included, so be sure to hit the 'no tip' button", which we did.
The process was fine with me - the told you the tip percent up front ahead of time (menu was also posted in the window by their entrance), and they did not try to get an additional tip out of you.