Some Tex-Mex is pretty true to Mex-Mex, and some isn't. Both can be good, and both can suck. Over the last couple of decades, it is getting even more mixed up. Some restaurants are doing Tex-Mex that is closer to Mex-Mex... and it is pretty farking good.
Like biggie said, if you get a DQ in this one, you are quite possibly an idiot.