Well, this is the place that got Centennial Toyota a star... it was that good! I admit that I'm an In N Out guy so I may be a little biased when it comes to burger places... but this place is a close second to In N Out.
I give Smash Burger higher marks then "5 Guys" because there is something about their burgers that stand out and is unique. I loved the egg buns and the Smash sauce was good, not quite In N Out's spread good but we were inspired to take my Girlfriends Dad back to Smash Burger the next day to try one. I loved that there were options when it came to sides, Smash Fries were ok, regular fries were better and the Onion Strings were awesome! Fries wise, SmashBurger has both 5 guys and In N Out beat!
Bonus points for having Cherry Coke (that worked) and Milk Shakes rather then peanuts. However, two people for lunch was just over $20 vs In N Out being about $12 so the value is still better at In N Out. I would say this, if Vegas didn't have an In N Out I would be just fine having Smash Burger as my substitute.