I’ve been doing some serious research on Tom’s Restaurant, the New York diner that “played” the exterior of Monk’s on Seinfeld, and I think I understand now why it was so special that it got not only a spot on one of the biggest sitcoms of all time, but also a song from Susanne Vega (the 1990 hit “Tom’s Diner”): because it’s so ordinary. There’s nothing more perfectly, classically New York than a greasy spoon open 24 hours, ready to remedy your hangover or your heartbreak with cheap food and coffee, ready to greet you by name or let you sink into the anonymity of a booth. A working-class joint that worked its way up to fame—so many of us identify with this arc that we’ll love the place no matter what the pancakes taste like. (The fries and grilled cheese better be good, though.)

There’s a hilariously long list of cranky reviews of Tom’s on Yelp and other customer-generated sites, many of which end with such melodramatic conclusions as, “This has ruined Seinfeld for me forever.” There are so many things wrong with this sentiment that I won’t even begin to enumerate them. But as occasional other reviewers have pointed out, these tourists have the place all wrong. One huffed, for instance, that his side of green beans tasted like it came out of a can. I would bet a fair amount that they did. If you want fresh-foraged haricots vert, go to some artisanal joint in Brooklyn, dude, then go home and fire up a Seinfeld DVD. There, order restored.

I was lucky enough to get a press screener for the unreleased documentary Tom’s Restaurant by Gian Franco Morini and Jesse McDowell. In it, I learned many more endearing things about the 40-year-old, family-owned eatery. Yes, of course, it’s famous, and it enjoyed its time in the spotlight, hosting radio DJs and a glitzy Maxim-sponsored viewing party the night of the series finale. Owner Mike Zoulis’ cousin even called to say he’d seen Mike on TV in Australia, being interviewed on CNN.

But the business hadn’t blown up all that much in the time Seinfeld was on the air. It did grow from Seinfeld-related tourism as the show went into syndication across the world. Zoulis and his family fielded offers to franchise or sell the restaurant, but they turned them down, happy to keep doing what they do well. “We feel that we have a successful formula here,” Zoulis told the filmmakers. “Maybe we’re old fashioned. Maybe we’re afraid of change.” He added, “It’s not like we were seeking fame and fortune. You can sit down, you can have a cup of coffee, you leave here with your wallet intact. What more can you ask for?”

Well, there are some more things the restaurant has done that you couldn’t possibly ask for, but they’ve done them all the same. They helped out a homeless crack addict who slept nearby, giving him food when he needed it; in exchange he often shoveled snow or spread salt on the sidewalks for them. Now clean, he frequents Tom’s still to show them he’s doing well. They stayed open during the citywide blackout to help people stay fed and offered electric outlets for cell phone charging to downtown refugees who were without power after Hurricane Sandy. Many patrons in the film cited a different sitcom when describing Tom’s: “It’s like Cheers. A place where everybody knows your name.”

Check out a trailer for the movie below: