I have to agree with Manticle on this one, same as Blue Corn in St. Kilda. Informed by tradition. I think it would come off a bit closer to traditional if access to quality traditional ingredients was a bit easier. They make a huitlacoche (corn mushroom - ahem, OK, corn smut) taco and of course have to use canned huitlacoche. From what I've read, in parts of Mexico it's a pretty down-home thing. Hell, looking at it you'd never try it voluntarily without someone saying, "Hey man, that blue turd-looking thing is GOOOOOOOOOD to eat!"
Mamasita's taco is very meh, but fresh huitlacoche will blow your mind completely, and happens to be traditional. But then they're not trying to be traditional. Mamasita's food was great for a while and then seemed to take a serious drop down after a couple years.
One of the funny things I have noticed is that a lot of the nouveau Mex places in Melbourne often have a lot of Indian chefs in the kitchen. The range of spices in Mexican food is mostly contained within Indian cooking, but the proportions are different, sometimes just slightly. Blue Corn is one example of a place where the folks in the kitchen know very well how to use the spices, but I think habit takes over and some of the dishes veer in the curry direction. I might be upset getting that if I was in the States or Mexico and got that dish, but here I just notice it and say thanks for the blessing of something good and quite, if not wholly, Mexican. There you go, time for someone to open a Mexican/Indian fusion restaurant.