I am in the infancy stages of my ramen exploration in Vegas. While I can't say that this is the best ramen I've ever had, it is the best I've had in Vegas so far. I always get whatever is their spiciest version of miso ramen on the menu. To be honest, this is why they've lost a star. It's really not that spicy. I was expecting some major heat, but it failed to live up to its title. Even so, I've been back twice because at least their hotter than the others. All the ingredients are fresh, and the chasu is tasty.
As for the service, I've had extremes. The first time I went during lunch, the waitress was short with guest and didn't ever come by to refill my tea. I had to walk to the counter and ask for more tea and water. When I did, it turned out everyone needed more water. She went through 2 pitchers. When I went back in the evening, it was a much better staff all around.
I'll give them 3.5 the first time and 4.5 the second time.