I always judge Mexican restaurants by their brand and rice, which I think are way better than Roberto's and for that reason alone I will keep coming back to Rivas. The menu is a lot like Roberto's but a bit simpler. It's split into different types of tacos, tortas, and quesadillas as well as all the classics.
I loved the idea of being able to choose a meat for my quesadilla so I went with the steak. Let me tell you, it was some high quality meat and I could tell it came straight off the grill. It was tender and not over-salted or over-spiced. Great flavor. The guacamole it came with seemed pre made but I could be wrong.
Naturally I wanted to try a second item to get a little bit of variety during my visit. I went with the al pastor fries. Again the theme continued with the meat--freshly cooked and even a like bit of crispness to it. The only thing I didn't like we're the fries were very very soggy and that's the only reason I'm giving it a four star review.
The salsa bar was very similar to Roberto's but both the red and green had far more flavor and were spicer, which I crave. However, the carrots and jalapeƱos only had one jalapeƱo in them, and I always grab 3 or 4 at Roberto's so that's a shame. Hopefully a mistake or something...
Check this place out, it's a great alternative to the 500 Roberto's stores that are here in Vegas.