Whether it is your local dine in restaurant like Denny's where it's an array of the general public or a classy fine diner where there is a dress code, service etiquette is the most important aspect.
The gentlemen that served me was everything a waiter should not be: Never once asked how the coffee was, checked to see how the food was (after he so conveniently walked up as I sat down and said you are going to have to wait awhile, no greeting before the rude message), seemed as it's the last place on earth he wanted to be (told the table next to me how unhappy he was) and kept calling me "bro".
First impression and couldn't be more disappointed. Never again.