3.5 stars for sure. A big star came off because our waitress managed to confuse french onion soup with clam chowder and then basically was confused when we told her it wasn't what we ordered.
Red Robin has a great selection of burgers and chicken sandwiches and their Vegan/Veggie alternatives are adequate for even the pickiest eaters. The bottomless fries with multiple dipping sauces is a great touch and the burgers are juicy and delicious. My only gripe with the burger itself is that it was way too messy and basically fell apart in my hands. Not sure if it was the soggy bun or the 2 lbs of sauce dripping out but it was an inconvenience and happens every time I eat here.
If you are looking for a highly priced, tasty burger Red Robin is definitely a good choice but there are plenty of places for less money that are much better in Las Vegas. Create in Summerlin still ranks much higher on my list.