Where I went to college, there was a great little burrito place, Pancheros*, and their tagline for their big 2lb "El Gordo" burrito was that it was "as big as your head." Two pounds, and not a single grain of rice. Tortilla, refried beans, meat of your choice, some cheese, some sour cream, maybe some salsa... wrap that shit up, put it back on the grill to sear the tortilla, you got your fuel for your drunken walk back to the dorm. Glorious. Went back there a few years ago, to relive the memories and I about gagged on the Chipotle-ized rice.
Now that I've had a few more, and experienced other chains that use rice too, I'm used to it, and it's alright but... it's definitely the inferior option. I highly recommend giving refried beans a try. Only reason I can think of using rice is for the cost. Once you go refried, you won't want to go back.
(* Just looked them up on Wiki to see if they documented their recipe, and discovered that although it's a chain now, my drunken memories are from their very first store.)
