While the vibes inside each restaurant are definitely different — BurgerFi being the more upscale version of Five Guys' classic fast-food joint flair — the menu basics are close competitors.
Quality-wise, I think both chains use ingredients that feel and taste fresh to me as a customer. From the buns to the veggies and even the patties, they both leave little to be desired.
Though I've been a longtime fan of Five Guys, I think I prefer the overall burger at BurgerFi because of its sturdy bun and flavorful meat. It's also less expensive, which is a draw for me.
After trying the fries from both chains, Five Guys' spuds reign supreme, in my opinion. The fact that they keep their flavor and texture even if you take a while to finish the massive portion is a characteristic I can't ignore.
While I think BurgerFi is a fast-casual chain with fancier-than-fast-food dishes — the menu includes specialty burgers and truffle fries — even when boiled down to the basics, I'd choose this smaller chain over Five Guys if they were right next to each other.