Just wanted to add to my first post, that for me, it is not just the quality of the service provided, but also how much I really like the servers level of friendliness, helpfulness, character and personality. I have (Not at Dl) encountered very poor servers, but because in the State Of California, in that industry, typically minimum wage is earned, which is $8.00 per hour. I still will leave a small tip, most definitely not 20%, more like 10% or less.
My experience last year, at The Blue Bayou was especially nice with our server, Diana. I do not remember unfortunately the name of my server this past August. She was nice, and efficient, however, she was no Diana. Anyway, I left her a 20% tip. I felt that it was warranted well enough. Diana's service, and friendliness, et al. though was most definitely worth above 20%.