Dreadfully mediocre. I don't think i've had a less flavorful burger anywhere, including at fast food joints.
We had a party of 6, so we were automatically charged the 18% gratuity despite the waiter forgetting my pepsi, and forgetting to have our garbage fries with no olives. While the fries were decent (as well as the garlic fries, although the tater tots were just ok), everyone agreed that the burgers were very plain, especially given they range from $11 - 25. The jalapenos on the Inferno weren't spicy at all, and the Standard doesn't even come with any sauce which makes the plain patty taste even more bland.
We came here because it was handy while we were staying at the Palazzo and didn't want to go far, but don't bother. Walk somewhere else.