Staff note: This post and the repsonses to it have been moved from the Dim Sum, San Francisco topic, to maintain focus.
I rarely eat dim sum these days. Cantonese food is way down my list of preferred cuisines in China. However, when I have had it, it has never been for lunch. In fact, the dim sum places here are nearly all shutting shop at around 11 am. Yum cha, the event at which dim sum is traditionally eaten is a strictly breakfast or brunch event. They open as early as 5 am and are packed. Also very noisy. Chinese people like a good shout with their breakfast.
Also, I don't recall ever seeing chow mein being served with dim sum. Not spring rolls often, either. Especially not now. Spring has long gone!