Where South Street sets itself apart from competitors like Five Guys is in the toppings. Cajun onions, garlic mayo, guacamole, etc. They also have toppings for the fries (both spices and poutine styles).
The regular burger is 519 calories and the small burger is 289 on a whole wheat bun.
The small fries is 400 calories with 1.5gr saturated fat.
See Nutrition info at the website (PDF). Really appreciate it when they offer this.