My family eats at City Diner 2-3 times a month. I would say that it has more of a neighborhood family restaurant feel to it than a diner, as its name would suggest.
The food is above average and the portions are generous. Prices are reasonable and they have specials that are usually a very good value. They have had a $9.99 steak special that is a great deal. The steak was somewhat under-seasoned but not bad considering that I don't think that I could have made one at home for that price.
The service has always been good. The servers are friendly. Food comes out of the kitchen very quickly. Usually this would cause alarm for me because it makes me think that everything is precooked and that they just reheat it when you order, but somehow they pull it off. Breakfast is especially fast (as it should be). I once ordered breakfast and then went to the restroom to wash my hands. When I returned to my table, my food was already sitting there!
The whole restaurant is clean including the restrooms. I have seen several employees cleaning various areas of the restaurant when they were not busy.