My first time at a Five Guys last Saturday for National Hamburger Day. I came here on a friends recommendation after seeing that BRGR's line was out the door.
I had the cheeseburger with sauteed mushrooms and sauteed onions. They went really light on the topping only under the bottom of the two toppings to the point I could barely taste them. I find it only marginally better than a McDonald's quarter pounder with cheese, as another reviewer commented. That much said In-n-Out doesn't do much for me either, so I can see how some might disagree.
I much prefer burgers where they grind their own beef and you can get something besides super well-done... I used to really like Fuddruckers before they went out of business.