Don't go for the dirty trays, the lack of napkins, the visibly overflowing garbage bins, the enormous television, the predictably forgetful counterman with one whole customer standing at the counter ("Was that for here, or to go?" Twice, now.) and the tepid level of heat your tongue inevitably finds at the core of the sandwich. No. Go for the way their beef shawarma *tastes*.
That would be the beef shawarma in pita. With hummus. No white sauce. Go for the unique, alien flavor of it, imparted by Cthulhu-knows what spices they use in the shredded lettuce, and whatever the hell those red pickled things are that they add to the garnish. The taste of the stuff is mesmerising.
Go because the taste of the stuff will send you to some Fritz Leiberish alternate universe. You'll be eating the fast food of Lankhmar. On Crescent.