I've been to this Shophouse restaurant 5/6 times and found the quality of food, service and atmosphere consistently good every time.
I also read the other reviews before writing my own. In relation to some of the negative comments, this is a single Shophouse, not a purpose built restaurant and most attention is placed on food and service rather than comfort. I agree it could be a bit lighter but it does add to the atmosphere.
The menu choice is limited but quality is great, particularly the pulled pork and chorizo. Full of flavour. I'm not an expert on Mexican food, but of all the Mexican restaurants in Bangkok this is the one I go back to. Fine dining environment no, relaxed quality, super tasty food, yes.