This is a simple taco/burrito joint attached to a Walgreens, which sounds terrible, and it truly doesn't lend itself to great results. That said, there are two things going for this place: 1) It's the only place to get a tofu taco or burrito in the whole of Palo Alto, from what I can tell and 2) It's in a less-trodden part of town, away from downtown or California Avenue, and therefore gets props for being in an area mostly lacking in food options.
I had an order of chips and guacamole ($4.25) and a "super tofu ranchero" burrito ($6.95) made vegan by omitting the cheese and sour cream.
The chips and guacamole was terrible. The guacamole was weirdly liquid-y and had a mass-produced taste; this is what guacamole would take like if McDonald's were making it. The chips, too, were either slightly stale or not fried long enough to get nicely crispy.
The burrito was also passable. It consisted of tofu cubes, rice, black beans, guacamole, lettuce and pico de gallo. I hate to say it, but the burritos at Chipotle are much better than the ones here: ironically, the Chipotle offerings are fresher and feel almost home-made, whereas Como Esta feels commoditized and strip-mall grade.
All that said, I would consider coming back for a simple tofu taco, or maybe give the burrito another shot with a whole wheat tortilla (I got mine with white flour, sadly, only because when you order they don't ask you what type of tortilla you want, and I found out only later that they offer whole wheat). Still, if I had to choose between this place and Chipotle, I am saddened to say that the chain restaurant wins out.