Okay, I just moved to the area and every time I drive by Burger320 I want to go in. Finally, I had time and we needed dinner so it was the obvious choice.
I ordered a GF (which they list as "girlfriend bun" - this makes me laugh because every single time I see "GF" written I think girlfriend) which was thin like a pancake with the vegetarian burger (read: mushroom) and the toppings of a Cayley burger (All sorts of goodness that comes with a turnip and carrot slaw). It was DELICIOUS and messy and glorious.
We also had white fries and they were off the chain. Like so good. Oh god I want them now. And my gentleman friend ordered the classic 320 burger, which he reported was "legit"
The staff was friendly and hilarious, gently poking fun at my difficult order. The coolest thing I saw was an older gentleman came in and he ordered his "usual" and couldn't remember what his wife wanted. The cashier was going to lend him her phone to call her, but the man who was cooking (who I am reasonably certain owns the joint and a million other joints) was like "Oh, Lana? She wants the chicken burger but spicy. Don't worry I'll make it". What the what?! That little old man felt so special and I was in awe of his memory and care for his customer.
Go there! Get cash first though as they are cash only.