I am aware of the policy at most restaurants of a automatic tip added to the bill for large parties. Here is my view on it. I am a good tipper - if the service is adequate, I will leave 20% - many times more, even up to 50%, if the service was unbelievable. However, if I go to a restaurant that wants to mandate what I have to tip (usually 15-18%), then that is the amount they will get, nothing more. I don't care what the service was like, so for a patron like me, the server is losing money. Just last week we had a birthday celebration at the Samba Room here in Orlando - very nice, relatively expensive restaurant. We had a large party, they added the tip - the server lost about $10 from what I would have tipped had she let me decide what to tip her. Most of my friends and family feel the same way - we understand that part of the cost of eating out is the tip, but to tell me what I should tip you is out of line. It doesn't keep me from going to restaurants that have this policy, but is sure does save me some money.
On the other hand, I have been a few time to restaurants where the server, while making change for me, decided that that extra change that she didn't currently have in her pocket wasn't worth going to someone to make change for and gave me back less than what my expected change should be. Most recently, my change should have been $6.12, but the server assumed that the 12 cents was hers and only brought me back $6. Her tip was 12 cents. That was not her decision to make regarding my money, but if she wanted to think I didn't care, she was mistaken. It is not the 12 cents that upset me, just the princple that it wasn't her decision to make on how I will spend my money, regardless of how much it is.