Hotel Tortuga has nice ambiance but I found the food woefully lacking. It's basically just heavy, mushy Mexican food served on fiesta ware.
I got the chilaquiles made vegan (~$9), though they were out of the vegan cheese and instead gave me some guacamole. Interestingly, they charged me extra for the guacamole, which showed a strange lack of attention to detail. Also, my dish came with many sizable chunks of real cheese, which also shows a sloppiness in the kitchen.
The dish was boring and heavy. It's the type of dish that becomes a soft, soggy mush within minutes of it leaving the kitchen; the tortilla chips wilt and disintegrate under the heat and weight and wetness of the sauteed, overly-soft vegetables. You get more mushy-starchy textures from the beans. It's basically just a bunch of standard Taco Bell ingredients dumped into a dish, with some salsa spread on top. I'd prefer thoughtfully spiced and seasoned vegetables put together into a whole dish; at Tortuga, you get unseasoned ingredients thrown together.
Tortuga also doesn't seem to carry vegan chicken anymore, so the dish came instead with ground-up chorizo tvp bits that didn't add much taste or flavor.
All told, a mediocre dish. The other options didn't look that interesting to me and the menu makes it hard to figure out what's vegan or veganizable.
One weird point: you can get free chips and salsa here, but it's DIY, and you pick some chips with tongs and put them into a small paper basket and then have to ladle your own salsa into a small paper cup. The whole thing is crazy and hard to do (the chips will fall out of the tiny paper basket, believe me).
Lastly, the service is friendly.
Those of you looking for good vegan Mexican food should look further west---Quesadilla, La Cocina Logan Square and El Faro, both in Chicago, do fabulous, fresh Mexican dishes with mockmeats and from-scratch seasonings. No fiesta ware, no tofu sour cream, but straight-up Mexican foods made with vegan meats and marinades. Flacos in Oakland is also a wonderful spot with deep-fried taquitos stuffed with soy chicken, as well as vegan polvorones.