I work super close to this Roberto's and anytime I'm getting the itchin' to stuff myself full of Carne' Asada randomly- I look no further than Roberto's!
I've heard it's 24 hours-but I never usually hit it up other than normal work hours. Let's keep the long story short. Roberto's is basically a mainstay in Las Vegas and located all over the place. They have specials everyday of the week I believe, but I never take advantage of them. There drive through is always full so I opt to go inside and order and take my time eating.
Basic seating, basic decoration, almost a fast food feel to them.
But man, there Carne' Asada burrito never leaves me hungry and I have to loosen my belt notch a few notches after I eat it. If I finish it all in one sitting (which I usually do) I want to go to sleep in my comfy cubicle chair for the rest of the day. Doesn't help at work. Haha!
Anyway, do yourself a favor and get sour cream extra inside of it. The standard pico de gallo and verde sauce is good, and I love watching all the people cram all the free carrots and cucumbers into little baggies like there gonna run out (which they do sometimes as your standing there.)
Always leave full & happy, with only a few bucks out of my wallet. I can't speak too much for the other items on the menu, I'm pretty partial to my Steak!
Cheers!
~Mb