I usually only go to Hey Lucy on Wednesdays for martinis (they have the special at both locations).
I went this past Saturday with a group of friends for dinner. Our service was painfully slow, our meals arrived at different times, and some people had settled the bills with the server before others had finished eating (she just brought around the bills as that end of the table finished).
I've been before in a group of 4, or even just as two people, and haven't noticed really slow service, but perhaps they also have more staff working on Wednesdays. I think I'll stay away on Saturday nights and stick with somewhere that can handle the crowds.