Had lunch here on a Sunday and it was almost completely deserted. Located next to an Asian video store and behind a mini-mart you might not notice it from the street at first. However, this thing is right across the street from the Hard Rock Casino so you should be able to find it with relative ease.
The food here is so-so. The best part about the pho here is the beef quality, which is pretty good. The broth, as far as pho places go, is really not that good. Tastes like they took some shortcuts and added a lot of extra flavoring. It really doesn't taste like very authentic pho to me. Too salty. Tastes too much like bullion. Noodles were fine and the Vietnamese coffee was pretty decent, but the imperial rolls were disappointing.
The service here was crappy - ordering was difficult, they brought us things we didn't order, and they never really checked on us. I had serious trouble understanding what our waitress was talking about, and that wasn't just the 3 hours on the blackjack table hangover.
This place would get 2 stars in SF but I understand it's Vegas, so pho might be hard to come by. Worth a shot if you are craving pho while fighting that hangover.